B978-0-323-04969-6.00013-6, 00013
ctr0065
Third EdiTion
Chiropractic
Technique
Principles and Procedures
Thomas F.
Bergmann, dC, FiCC
Professor, Chiropractic methods department
Clinic Faculty, Campus Clinic
northwestern health sciences University
Bloomington, minnesota
david h.
Peterson, dC
Professor,
Division of Chiropractic Sciences
Western States Chiropractic College
Portland, Oregon
with 1340 illustrations
i
BERGMANN, 978-0-323-04969-6
3251 Riverport Lane
St. Louis, Missouri 63043
Chiropractic Technique Principles and Procedures
Copyright © 2011, 2002, 1993 by Mosby, Inc., an affiliate of Elsevier Inc.
978-0-323-04969-6
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Notice
Knowledge and best practice in this field are constantly changing. As new research and experience broaden our
knowledge, changes in practice, treatment and drug therapy may become necessary or appropriate. Readers are
advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer
of each product to be administered, to verify the recommended dose or formula, the method and duration of
administration, and contraindications. It is the responsibility of the practitioner, relying on their own experience
and knowledge of the patient, to make diagnoses, to determine dosages and the best treatment for each
individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the
Publisher nor the [Editors/Authors] [delete as appropriate] assumes any liability for any injury and/or damage
to persons or property arising out of or related to any use of the material contained in this book.
The Publisher
Library of Congress Cataloging-in-Publication Data
Bergmann, Thomas F.
â•… Chiropractic technique: principles and procedures / Thomas F.
╇ Bergmann, David H. Peterson. – 3rd ed.
╇╅ p. ; cm.
â•… Peterson’s name appears first on the earlier edition.
â•… Includes bibliographical references and index.
â•… ISBN 978-0-323-04969-6 (hardcover : alk. paper)
╇╅ 1.╇ Chiropractic. 2.╇ Manipulation (Therapeutics) I.╇ Peterson, David H., 1952- II. Title.
╇╅ [DNLM: 1. Manipulation, Chiropractic–methods. 2. Chiropractic–methods. WB 905.9 B499c 2011]
╇╅ RZ255.B47 2011
╅╇ 615.5'34–dc22
2010004358
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Foreword
A
h! Where to begin? I’ve written books, chapters, papers,
and editorials, but I think that writing a foreword can be
the most challenging task. On the one hand so great is
my admiration of this Third Edition of Dr. Tom Bergmann’s and
Dr. Dave Peterson’s Chiropractic Technique that I have to restrain
myself from writing what may substitute for an introductory
chapter. On the other hand I’ve been given a rare opportunity to
introduce readers to an extraordinary textbook, and I want to use
my space wisely.
First, the traditional and well-deserved laudatory comments:
this third edition of a now legendary chiropractic textbook offers
old and new readers an encyclopedic treatise of chiropractic manual methods (Principles and Procedures as described in the subtitle)
referenced with the most up-to-date evidence, lavishly illustrated,
occasionally controversial but always rational, and true-to-form
for these experienced authors, eminently readable. The most valuable addition is the availability of the text in electronic format
(e-book), and the access to the Evolve website with video demonstrations of all assessment procedures and adjustive techniques.
I can only imagine how valuable such an aid might have been
during my own chiropractic education in the early 1970s. At
that time we mostly learned from inconsistent personal instruction and crude drawings of static positioning. However, by using
this wonderful reference work the next generation of chiropractors promises a whole new standard of consistency of care, not to
mention the opportunity for instructors to design authentic and
consistent assessment of their learners. Each of the chiropractic
manual and manipulative procedures has been named to concur
with common practice and especially the nomenclature used by
the National Board of Chiropractic Examiners, which adds to the
utility of this text for all students.
Chiropractic history is a special interest of mine, and I can
admit to the fact that many common manipulative procedures are
founded on a long tradition of empirical evidence, some dating
back centuries. This said, our current understanding (and hence,
our refinement) of these procedures is based on modern sciences
such as biomechanics and kinesiology, engineering, and diagnostic imaging. Elements of manipulative technique such as the idea
of “pre-stressing” an articulation have acquired a new importance
and allow for the first significant refinements of some manipulative
techniques in many years. Staying abreast of such developments
is the professional responsibility of every practicing chiropractor.
This textbook provides a comprehensive reference for maintaining
currency in the art and science of our field.
In adding my final comment about this new textbook, perhaps
I will be a little controversial myself. In Chapter 3, the authors
state that the concept of subluxation serves as a defining principle as well as the source of contentious debate and disagreement
within the profession. I agree with this statement and I think that
many modern and scientifically based chiropractors recognize the
significance of this statement and the nature of the double-edged
sword of this phenomenon we have historically known as the subluxation. Another double-edged sword is the great variety of chiropractic professional approaches and practices that are observed
around the world today. Many have added to our diversity and
sparked debate and the development of better, more effective care.
In my view, however, this has also contributed to an often dogmatically based divisiveness, a lack of clear consensus on scope
of practice and professional standards. It is my sincere hope and
expectation that this textbook will contribute to a more visible
consistency of approach to care in future generations of chiropractors, not forgetting those currently in practice with many
years of practice remaining. Such a consistency of our professional
approach to patient care is absolutely essential if we are to assume
a rightful role in our nation’s health care system. Were it in my
power, I would insist that every single chiropractor and chiropractic student own and study this book and put into practice what
Bergmann and Peterson have so masterfully described.
Michael R. Wiles, DC, Med
v
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pre0085
Preface
T
he third edition of Chiropractic Technique thoroughly
�discusses the use of the manual therapies with emphasis
on thrust techniques in an unbiased and rational manner, based on and supported by current evidence, and continues
its focus on teaching students of chiropractic and manual therapy.
It is a practical and comprehensive presentation of the fundamental and advanced skills necessary to evaluate joint function and to
deliver thrust and nonthrust techniques. As such it should help
standardize the teaching and application of these procedures.
The third edition is also available as an electronic text. This
�feature allows for the addition of video demonstrations for the
evaluative and adjustive procedures. From the inception of this
text the authors have realized the enormous teaching value of having video clips to accompany the evaluation and treatment procedures. This feature provides the visual content that is so important
for the development of manual skills and self-directed learning.
Also new to the third edition is the naming of each of the adjustive procedures. It is necessary to assign a clear and specific name to
each technique procedure for teaching and testing purposes. The
adjustive techniques have been given names that are based on the
involved joint/region, patient position, contact used by the clinician, body part contacted, and any necessary additional information (i.e., push, pull, with distraction, etc.), as well as the induced
joint movement. These names follow the patterns used by the U.S.
National Board of Chiropractic Examiners and are designed to be
helpful in the teaching and testing for competence.
The organization of the third edition remains the same with
each chapter able to stand on its own. It is not necessary to read
the information in one chapter to understand the material in
another.
Chapter 1 provides an updated look at the past, present, and
future aspects of the profession of chiropractic. It also draws attention to other professions that incorporate manipulative therapy
and includes expanded information on the philosophical roots of
the chiropractic profession.
Chapter 2 presents the musculoskeletal anatomy and basic biomechanical principles necessary to understand and apply chiropractic adjustive procedures. It has been updated with additional
information on the effects of loads on all forms of connective tissue as well as the relationship between forces applied to the body
and the consequences of those forces on human motion. Chapters
3 and 4 have been revised and supported with current references.
Chapter 3 is a comprehensive discussion of the basis for evaluation of joint dysfunction identifying important, relevant, and
defensible concepts for the role that the musculoskeletal system
plays in health and disease. It takes a critical look at the chiro-
practic manipulable lesion historically labeled as subluxation and
also commonly referred to as joint dysfunction. Clearly this topic
is one of passion and contention. We have attempted to discuss
issues including definitions and theoretical models that have supportive evidence. Moreover, we discuss and describe the various evaluative procedures used to identify the presence of joint
dysfunction with a corresponding Appendix demonstrating the
known reliability and validity of the procedures.
Chapter 4 reviews the current understanding of manipulative
mechanics, providing insight into current research and theoretical
models of effects, or what happens when various forms of manual
therapy are applied. We believe this chapter is very important to
anyone seeking to become a user of thrust manipulation as it presents information relating to adjustive vectors, forces, and which
joints and tissue may receive the majority of applied force. It suggests that what we say we have been doing and what we really are
doing may be two entirely different things.
Chapters 5 and 6 have been updated with some new procedures, and other procedures have been modified. However, the
significant change is in the layout of these two chapters. They are
designed as a practical manual with technique descriptions that
are closely associated with the illustrations and grouped by patient
position. The names are changed to reflect the U.S. National
Board of Chiropractice Examiners format.
Chapter 7 presents information on the application of mobilization, traction, and soft tissue procedures. Clearly, the High Velocity, Low Amplitude (HVLA) form of manual procedure is not
indicated or tolerated by all patients and other forms of manual
therapy should be applied. This chapter provides the rationale and
description for many of nonthrust techniques.
We continue to believe that the text’s distinguishing strong
point is its comprehensive and extensively researched rational
approach to the application of chiropractic adjustive techniques.
The breadth of the topics covered makes it ideally suited as both a
core teaching text for chiropractic students and a reference text for
anyone using manual and manipulative therapy.
We are very pleased with the adoption of this text at a number
of national and international chiropractic institutions and that the
U.S. National Board of Chiropractic Examiners lists it as a reference for tests on chiropractic practice. Our goal for this text is to
have it be a comprehensive source to assist in the standardization
of teaching chiropractic diagnostic and adjustive methods.
Thomas F. Bergmann, DC., FICC
David H. Peterson, DC
vii
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ack0090
Acknowledgments
A
third edition of a textbook can only occur through continued acceptance and use. Thanks must therefore go to all
of the students, faculty, and practitioners who have found
Chiropractic Technique a valuable educational resource.
We wish to acknowledge the roles of many individuals in the production of this edition: the photographic talents of Glen Gumaer
on the First Edition, Arne Krogsven on the Second Edition, and
Greg Steinke on the Third Edition; Nick Lang for the graphic
artwork in the First Edition and Jeanne Roberts in the Second
Edition; Dr. Janice Justice, Dr. Fred Rhead, Dr. Janet Preckel, Dr.
Lolin Fletcher, and Dr. Andrew Baca for serving as models in the
First Edition; Dr. Stacy Thornhill, Dr. Sarah Macchi, Dr. Torbin
Jensen, Dr. Arin Grinde, and Brian Hansen for serving as models
in the Second Edition; Andrea Albertson, Lindsey Baillie, Matt
Christenson, Ayman Hassen, David Landry, Christine Rankin,
Kristen Rogney, Haj Soufi, Kory Wahl, and Pler Yang for serving
as models in the Third Edition.
Appreciation and gratitude goes to Dr. Stacy Thornhill and
Dr. Joe Cimino for their expertise in differentiating and defining the various soft tissue techniques, to Dr. Tom Davis for the
concepts of distractive and motion-assisted procedures, and to
Dr. Bill Defoyd for his insight and suggestions concerning
McKenzie methods.
Finally, we would like to express sincere gratitude to all of the
individuals at Elsevier, Inc., who have maintained faith in us and
this book to see it through to a third edition. Specifically, we thank
Kellie White, Kelly Milford, and Sara Alsup.
D.P. and T. B.
ix
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<CID>
Contents
Chapter 1: General Overview of the Chiropractic
Profession
1
The Past
The Present
The Future
Conclusions
Chapter 2: Joint Anatomy and Basic
Biomechanics
Fundamental Concepts, Principles, and
Terms
Joint Function
Mechanical Forces Acting on Connective
Tissue
Properties of Connective Tissue
Models of Spine Function
Chapter 3: Joint Assessment Principles and
Procedures
The Manipulable Lesion
Subluxation
Vertebral Subluxation Complex
Joint Subluxation/Dysfunction Syndrome
Spinal Listings
Clinical Evaluation of Joint Subluxation/
Dysfunction Syndrome
Clinical Documentation
Chapter 4: Principles of Adjustive Technique
Classification and Definition of Manual
Therapies
Joint Manipulative Procedures
Soft Tissue Manipulative Procedures
Indications for Adjustive Therapy
Mechanical Spine Pain
Joint Subluxation/Dysfunction Syndromes
Contraindications to and Complications of
Adjustive Therapy
Effects of Adjustive Therapy
Application of Adjustive Therapy
1
3
9
10
11
11
20
23
26
33
35
36
36
37
47
47
47
82
Chapter 5: The Spine: Anatomy, Biomechanics,
Assessment, and Adjustive Techniques
145
Structure and Function of the Spine
Evaluation of Spinal Joint Function
Identification of Joint Subluxation/
Dysfunction Syndrome
Cervical Spine
Thoracic Spine
Thoracic Adjustments
Lumbar Spine
Pelvic Joints
Chapter 6: Extraspinal Techniques
Role of the Peripheral Joints
Temporomandibular Joint
Shoulder
Elbow
Wrist and Hand
Hip
Knee
Ankle and Foot
145
146
151
152
188
211
233
262
283
283
283
294
315
326
337
349
364
Chapter 7: Nonthrust Procedures: Mobilization,
Traction, and Soft Tissue Techniques
381
Joint Mobilization
Manual Traction-Distraction
McKenzie Method
Cranial Manipulation
Soft Tissue Manipulation
Conclusions
381
384
387
391
393
418
84
Glossary
419
84
84
88
89
89
90
Appendix 1: Named Chiropractic Techniques
426
Appendix 2: Compilation of Reliability Studies
on€Joint Evaluation Procedures
429
Appendix 3: Compilation of Validity Studies
on€Motion Palpation
440
References
441
Index
469
92
105
120
xi
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c0005
General Overview of the
Chiropractic Profession
OUTLINE
THE PAST
Philosophic Roots
THE PRESENT
Basic Principles
T
1
3
3
3
Chiropractic Education
Licensure
Scope of Practice
Patient Access and Chiropractic
Utilization
he chiropractic profession is only a little more than a century
old, but manipulation in its various forms has been used to
treat human ailments since antiquity. Although no single
origin is noted, manual procedures are evident in Thai artwork
dating back 4000 years. Ancient Egyptian, Chinese, Japanese, and
Tibetan records describe the use of manual procedures to treat
disease. Drawings demonstrate the application of this treatment
form from the time of the ancient Greeks through the middle ages
in various parts of the eastern and western world. Manipulation
was also a part of the North and South American Indian cultures.
Certainly, Hippocrates (460–355 bc) was known to use manual
procedures in treating spinal deformity, and the noted physicians
Galen (131–202 ad), Celsus, and Orbasius alluded to manipulation in their writings. The nineteenth century witnessed a rise
in popularity of American and English “bonesetters,” the most
well known being Mr. Hutton, who influenced the thoughts and
writing of Sir James Paget and Wharton Hood. Bonesetters were
often called upon to provide treatment for many types of maladies. Bonesetting was often practiced by families. It evolved from
a lay practice developed from the peasant revival of manipulation
after it went underground during the seventeenth century.
It was not until the days of Daniel David Palmer and Andrew
Taylor Still, the founders of chiropractic and osteopathy, that
these procedures were codified into a system. Palmer and Still
both became acquainted with bonesetters and bonesetting techniques. In addition, the two men practiced magnetic healing,
a reflex therapy that on occasion used powerful paraspinal massage.1 Bonesetting and magnetic healing were instrumental in the
founding of chiropractic and osteopathy. The early days of chiropractic and osteopathy represented major attempts to place manual
procedures on firmer ground, and although the major developments in manual manipulative procedures in the late nineteenth
century were largely American, developments were also occurring
in other locations around the globe. At the same time, bonesetters
were working in the United States and England and continued to
do so into the early twentieth century. Bonesetters continue today
to have an effect on health care delivery in Japan. While chiropractic was developing in the United States under the leadership
of D.D. Palmer and his son, B.J. Palmer, medical manipulators
from around the world were also making significant advances, as
were early osteopathic researchers. The works of Mennell, Cyriax,
Paget, and others are important in this regard.
5
6
6
Chapter
1
Research
Standard of Care and Guidelines
THE FUTURE
CONCLUSIONS
7
8
9
10
6
Both chiropractic and osteopathy chose to focus on the musculoskeletal system, although in philosophically divergent ways.
Andrew Still placed great emphasis on the somatic component
of disease, largely involving the musculoskeletal system, and on
the relationship of structure to function. Palmer postulated that
subluxation, or improper juxtaposition of a vertebra, could interfere with the workings of the human nervous system and with
innate intelligence, that power within the body to heal itself. Both
emphasized the role the musculoskeletal system played in health
and disease.
Coulter has described the historical concepts of chiropractic
that initially defined the young and growing profession, and the
emergence of a developing philosophy of care.2 He suggested that
chiropractic distinguished itself as a primary contact healing art
by advocating for an alternative type of care, and advancing the
specific philosophic tenets of critical rationalism, holism, humanism, naturalism, therapeutic conservatism, and vitalism in the care
of patients. Many of these tenets have been well established and
significantly advanced by the profession.3
However, to succeed in an environment as dynamic and volatile as health care, it is critical to distinguish between those aspects
of a given profession that are vital to it and those aspects that are
inessential and often create costly distractions.4 To begin to understand the aspects of the chiropractic profession that are either vital
or inessential to the profession’s identity, a look at the past, the
present, and the future is necessary.
THE PAST
Daniel David Palmer (1845–1913; also known as D.D. Palmer)
is considered the “father” of chiropractic. He came to the United
States from Port Perry, Ontario, Canada, in 1865. He spent the
next 20 years in such various occupations as farming, beekeeping,
and store sales. In 1885, he opened a practice as a magnetic healer
in the city of Davenport, Iowa, although he had no formal training in any healing art.
During the nineteenth century, various forms of spiritualistic
and metaphysical speculation existed, all of which piqued Palmer’s
curiosity. He studied and was influenced by Mesmer’s concept of
animal magnetism and Mary Baker Eddy’s spiritual concepts used
in her Christian Science healing. During this same time, Thoreau
and Emerson’s transcendentalist philosophy, which emphasized a
1
2
| Chiropractic Technique
love of nature and independence of thought, provided a supportive environment for the pioneers of new healing methods, including D.D. Palmer.5 Palmer was able to blend recognized spiritual
and metaphysical concepts together with then-current scientific
principles to create a unique ethos for the chiropractic healing
art.6
His formulation of chiropractic practice and theory purportedly developed from his application of a manual thrust, which he
called an adjustment, to Harvey Lillard in September 1895 (coincidentally and significantly, the same year that Roentgen discovered the x-ray). This event has moved beyond that of a simple tale
to an apocrypha. As the story goes, this manual adjustment was
directed to the fourth thoracic vertebra and resulted in the restoration of Mr. Lillard’s lost hearing. From the reasoning used to
devise this treatment, Palmer then applied similar lines of thought
to other individuals with a variety of problems, each time using
the spinous process of a vertebra as a lever to produce the adjustment. Palmer was the first to claim use of the spinous and transverse processes of the vertebrae as levers for manual adjustment
of the spine—in effect, short lever contacts. This constituted the
initiation of chiropractic as an art, a science, and a profession.
Palmer wrote:
I am the originator, the Fountain Head of the essential principle
that disease is the result of too much or not enough functioning.
I created the art of adjusting vertebrae using the spinous and transverse processes as levers, and named the mental act of accumulated
knowledge, function, corresponding to the physical vegetative
function—growth of intellectual and physical—together, with the
science, art and philosophy of Chiropractic.7
From this nearly chance opportunity came the outlines of the
profession. Palmer developed the concept of a “subluxation” as
a causal factor in disease, through the pressure such “displacements” would cause to nerve roots. Within 2 years of the initial
discovery, Palmer had started the Chiropractic School and Cure
and soon had his first student. By the year 1902, Palmer’s son,
Bartlett Joshua (usually referred to as B.J.), had enrolled in his
father’s school and 2 years later had gained operational control of
the institution, becoming president in 1907. He maintained this
post until his death in 1961.
Animosity between father and son developed. Palmer clearly
stated that the only principle added by B.J. Palmer was that of
greed and graft; he aspired to be the discoverer, developer, and
fountainhead of a science brought forth by his father while he was
a lad in his teens.7 The elder Palmer left the school of his name
and traveled around the country, forming at least four other chiropractic schools in California, Oregon, and Oklahoma. He was
also placed in jail for a short time for practicing medicine without
a license. Although he might have been able to avoid jail by paying a small fine, he believed he had a more important principle
to uphold. Palmer was not the last to be jailed for this crime; the
process of jailing chiropractors for practicing medicine without a
license continued into the next two decades.8 Preoccupation with
the legal right to practice chiropractic no doubt led the profession to focus resources on political, ideologic, and economic concerns, rather than on research that might have influenced medical
scientists.9
D.D. Palmer died in 1913 after enjoying only a short reconciliation with his son, B.J., who had by that time led the original Palmer School for nearly 7 years. In 1906, D.D. Palmer had
already forsaken education at the original Palmer School. That year
was also significant because it marked the first philosophic differences within the fledgling chiropractic profession. John Howard,
one of the first graduates of the Palmer School, was unable to
accept many of the philosophic beliefs relative to health care that
B.J. Palmer was now openly espousing. B.J. had by then begun
to preach that subluxation was the cause of all disease. Howard
therefore left the Palmer School and founded the National School
of Chiropractic not far from Palmer’s school in Davenport. As
Beideman had noted,10 Howard wanted to teach chiropractic “as it
should be taught” and therefore moved the school to Chicago,
believing that chiropractic education required coursework in the
basic and clinical sciences, including access to laboratory, dissection, and clinics. These two schools (now colleges) still exist today.
Willard Carver, a longtime friend of D.D. Palmer and the
attorney who defended him when he was arrested for practicing
medicine without a license, decided to take up the profession of
chiropractic as well. After D.D. sold the chiropractic school to
B.J., Carver began to distance himself from the Palmers. He never
had a strong relationship with B.J., and because of disagreements
on the nature of subluxation and scope of practice, he began his
own school in Oklahoma.
Carver viewed chiropractic practice in a manner opposed to
that of the Palmers. Carver followed what he called a structural
approach, which was essentially a systems approach to subluxation.
In his view, disrelations in spinal joints were the result of compensatory patterns and adaptations arising from other subluxations.
He was also an advocate for other therapeutic procedures beyond
adjustment that were at times outside the common scope of chiropractic practice, such as physiotherapy. This put him very much
at odds with the Palmerite approach to chiropractic.
Carver is equally well known for his legal and legislative efforts
on behalf of the profession. Not only did he establish schools of
chiropractic in several cities, he also wrote eight influential early
chiropractic texts, published a college journal (Science Head News)
that provided perspectives different from the prevailing Palmer
view, and helped establish licensing laws for the chiropractic profession where none existed before.
Other chiropractic institutions were also being founded all
over the country, and there was more and more internecine warfare among practitioners. B.J. Palmer had set himself up as the
protector of a fundamental form of chiropractic (today referred to
as straight chiropractic).
From 1910 to 1926, Palmer lost many important administrators, most of whom left to form their own institutions. Furthermore,
from 1924 until his death in 1961, he was a titular leader only, keeping the flame for a fundamentalist minority and battling with
most of the profession, which he saw as inevitably following the
osteopathic moth into the seductive medical flame.11
Regardless of the philosophic issues that were debated then,
and that still divide the profession today, it is possible that without
B.J. Palmer’s missionary zeal and entrepreneurial brilliance, the
chiropractic profession would not exist as it is today. B.J.’s title as
the “developer” of chiropractic was honestly earned.
Chapter 1â•… General Overview of the Chiropractic Profession |
Philosophic Roots
Spiritualism, which developed in the United States in the 1840s
and is based on the simple premise that humans are dual beings
consisting of a physical and a spiritual component, spawned a large
array of interrelated religious, healing, and paranormal investigative groups.12 Spiritualists believed that the physical element (the
body) disintegrates at death, but the spiritual element (the soul,
spirit, personality, consciousness, etc.) continues exactly as it was,
but in another plane of existence: the “spirit world” or heaven.
American transcendental notions also evolved during this
period and helped formulate the influential philosophy of Ralph
Waldo Emerson. Emerson’s concept of a dual mind, which incorporates both innate and educated elements, were very similar to
D.D. Palmer’s postulates and probably had a significant influence on Palmer’s early health care philosophy and theories.13 D.D.
Palmer stressed the concept and importance of the innate mind
and its role in self-regulation and restoration of health. He stated
that “spirit and body” compose a dualistic system with “innate
and educated mentalities,” which look after the body physically
within its surrounding environments.13 This idea of innate intelligence forms a critical part of a 1956 work by B.J. Palmer in which
he states, “Innate is the ONE eternal, internal, stable, permanent
factor that is a fixed and reliable entity, does not fluctuate up and
down scales to meet idiosyncrasies.”14
D.D. Palmer and his early followers emphasized health and
the absence of disease over the management of disease. Early chiropractic theory emphasized the important role of the neuromusculoskeletal (NMS) system, specifically the spine, in treating and
preventing disease. The concept was that a structural problem
within the spine contributes to altered musculoskeletal and neurologic function and diminishes the ability of the body to heal
itself.15 Palmer asserted that either too much or too little nerve
energy is “dis-ease.” Moreover, he believed that disease was the
result of internal imbalances involving hyperfunction or hypofunction of organs and systems rather than the result of something
external that invades the body.
Osteopathy was also emerging at the same time and within the
same philosophic environment. Andrew Taylor Still, the father of
osteopathy, was a strong believer in Spiritualism. He stated, “We
say disease when we should say effect; for disease is the effect of a
change in the parts of the physical body. Vis medicatrix naturae to
the osteopath declared that disease in an abnormal body was just as
natural as is health when all parts are in place.”16
In addition to his interest in Spiritualism, D.D. Palmer also
dabbled in other occult philosophies of his day. He first began
his practice as a magnetic healer in Burlington, Iowa, and would
in years to come write extensively on his thoughts about intrinsic
“inner forces.” He went on to label the inner forces and their selfregulating effects as innate intelligence. He reasoned that health
could be maintained if the body’s innate intelligence was functioning properly. Diseases were viewed as conditions resulting from
either an excess or deficiency of this function.17 In contemporary
health care the body’s ability to self-regulate and maintain internal
equilibrium is referred to as homeostasis.
The early chiropractic focus on the philosophy of chiropractic
and its distinct model of health care did not eliminate internal
3
debate concerning the need for scientific training and investigation.
From the early days of chiropractic’s founding, there were diverging views and debates between those stressing vitalism (the belief
that the principles that govern life are different from the principles
of inanimate matter) and those stressing a scientific approach to
practice. D.D. Palmer believed, as noted by Waagen and Strang,
that both approaches (the vitalists and the scientists) were important and that the concept of innate intelligence, which formed
the early cornerstone of the philosophy of chiropractic, could be
incorporated with a scientific approach to chiropractic.15
Many of the early chiropractic debates and divergent positions concerning its philosophy and health care model persist.
As a result, the philosophy of chiropractic suffers from a lack
of clarity and understanding of its boundaries.18-23 There is no
demonstrable evidence that a body of content has been agreed
upon. It is imperative that the chiropractic profession clearly
delineate what exactly is meant by the philosophy of chiropractic
and codify its content.24
THE PRESENT
Basic Principles
The broad chiropractic model of health care is one of holism.
In this model, health is viewed as a complex process in which
all parts and systems of the body strive to maintain homeostatic
balance against a dynamic environment of internal and external change. The human body is perceived as being imbued at
birth with an innate ability (innate intelligence) to respond to
changes in its internal and external environment. Earlier health
care pioneers saw this as proof of the healing power of nature, vis
medicatrix naturae. This concept emphasizes the inherent recuperative powers of the body in the restoration and maintenance
of health and the importance of active patient participation in
treating and preventing disease. The presence of an inherent
ability within the organism to influence health and disease has
been described by many different health care disciplines and is
listed in Table 1-1.
Table 1-1
ames Given to the “Subtle” Energy
N
of the Body Believed to Influence
the Body in Health and Disease
Energy Name
Originator
Prana
Chi
Xi
Libido
Orgone energy
Elan vitale
Innate intelligence
Vis medicatrix naturae
Biochemicals of emotion
Hindu
Chinese
Japanese
Freud
Reich
Bergson
Chiropractic
Medicine
Pert
4
| Chiropractic Technique
Broad-scope chiropractic care is committed to holistic health
care and working with patients to optimize their health. Although
the chiropractic profession’s major contribution to overall health
is through the evaluation and treatment of NMS disorders, it is
common for chiropractic physicians to also counsel patients on
other lifestyle issues such as diet, nutrition, exercise, and stress
management.
The contemporary practice of chiropractic maintains its focus
on the evaluation and conservative treatment of NMS disorders
and the important relationship between the functioning of the
NMS system and overall well-being and health. Dysfunction or
disease of the musculoskeletal system in any form is viewed as having the potential to create disorders of the locomotor system that
may lead to impaired functioning of the individual. This model is
supported by the underlying principle that stresses the important
interrelationship that exists between structure and function of the
human body.
In addition to specializing in the adjustive (manipulative) treatment of disorders of the spinal and extremity joints, it is common
for chiropractors to include other treatment procedures in patient
management and health promotion. Common therapies applied
include dietary modification, nutritional supplementation, physical therapies, and exercise.
The chiropractic profession considers the musculoskeletal system to be a clinically neglected component of the body, although
musculoskeletal disorders are common and account for significant
amounts of lost time at work and recreation. The musculoskeletal
system therefore deserves full consideration and evaluation whenever patients are seen, regardless of the complaint causing them
to seek care.
The musculoskeletal system should be viewed as part of the
whole body and subject to the same intensive diagnostic evaluation as any other system in the body. The musculoskeletal system
is involved in so many alterations of function that it demands such
attention and should not be removed from consideration in diagnosis, even when the initial problem appears removed from the
musculoskeletal system.
Moreover, the human musculoskeletal system accounts for
more than half of the body’s mass and is its greatest energy user.
The large amounts of energy required by the musculoskeletal system must be supplied through the other systems in the body. If the
musculoskeletal system increases its activity, an increased demand
is placed on all the other body systems to meet the new, higher
energy demands. Chiropractic notes that the presence of disease
or dysfunction within the musculoskeletal system may interfere
with the ability of the musculoskeletal system to act efficiently,
which in turn requires greater work from the other systems within
the body.
An important principle of chiropractic is that because the nervous system is highly developed in the human being and influences all other systems in the body, it therefore plays a significant
role in health and disease. Although the exact nature of the relationship between dysfunction of the musculoskeletal system and
changes in neurologic input to other body systems is not known,
an enduring basic principle of chiropractic is that aberrations in
structure or function can have an effect on health and the body’s
sense of well-being. The nervous system’s effects on the body’s
ability to fight disease through the immune response demonstrate
this concept.25
The nervous system also communicates with the endocrine system to maintain a state of homeostasis, defined simply as physiologic stability. This tendency of the body to maintain a steady
state or to seek equilibrium despite external changes, referred to as
ponos by Hippocrates, is the underlying theme in Palmer’s original
concept of innate intelligence influencing health.
Manual procedures and, specifically, the adjustment are applied
to address local NMS disorders and to improve NMS function.
A consequence of improved NMS function may be improvement
in the body’s ability to self-regulate, thereby allowing the body to
seek homeostasis and improved health. In Haldeman’s outline of
this process, manipulative therapy improves the function of the
musculoskeletal system, which then causes a change in the input
from the nervous system, which in turn may have a positive effect
on other NMS tissue, organ dysfunction, tissue pathologic condition, or symptom complex.26 Reflex mechanisms that support
these ideas have indeed been documented, although the effects of
manipulation on these reflexes have yet to be adequately assessed
and demonstrated.27-30
Palmer developed his model of the effects on the nervous system through the belief that subluxation affects the tone of the
body. In this model, tone refers to the efficiency of the nervous
system and to the ability of the body to self-regulate its processes
properly. This view was in opposition to the medical thought of
the day, which focused on the germ theory and its relationship to
disease.
Although many of the early forebears in chiropractic postulated subluxations as the root cause of all health care disorders and
a “one cause, one cure” approach to health, the monocausal theory
of disease has now been rejected by the overwhelming majority of
practicing chiropractors. Chiropractors today certainly accept the
existence and reality of germs and the role they play in creating
disease. Both the chiropractic and medical paradigms recognize
the health of the individual and his or her resistance to infection as
critical factors. Furthermore, the chiropractic profession views the
host’s susceptibility as depending on a multitude of factors. The
chiropractic model postulates that the presence of joint dysfunction or subluxation may be one such factor serving as a noxious
irritant to lower the body’s ability to resist disease. Within this
paradigm, removal of joint dysfunction or subluxation becomes
an important consideration for optimal health.
The value and importance of adhering to early chiropractic
philosophic models of health and disease are debated. Some argue
for strict adherence to an early fundamental paradigm because of
fear that divergence from fundamental core values will lead to the
dilution of the profession’s unique health care approach. Others
argue that unwavering adherence to a particular belief system
creates a climate of anti-intellectual dogma that retards the profession from investigating and differentiating effective from ineffective diagnostic and treatment procedures. Many of the historic
philosophic chiropractic tenants are considered to fall within the
realm of a belief system that can neither be refuted nor confirmed
through research. Certainly the profession’s early adherence to its
core principles helped established the profession as a unique and
valuable branch of the healing arts. These core values continue to
Chapter 1â•… General Overview of the Chiropractic Profession |
support the profession’s conservative approach to health care and
its emphasis on the body’s inherent recuperative powers. However,
it is probable that unwavering adherence to core values does create a climate that inhibits professional self-appraisal and clinical
research. Questions concerning clinical effectiveness and whether
“chiropractic works” are not answerable with philosophic debate.
Technically, philosophy asks questions about the nature of
truth (epistemology), reality (metaphysics), the good (ethics), and
the beautiful (aesthetics).31 None of these is susceptible to empirical scientific inquiry. Proving that “chiropractic works” has been
a loudly expressed goal of the profession that offends scientific
sensibilities. Concepts based on faith or intuition must not be
confused with scientific theory validated by empirical data or facts.
A profession, with all its procedures and practices, cannot be
demonstrated to “work.” It has not been said that research proves
that medicine or dentistry works; rather, specific studies are cited
identifying that a specific procedure is effective for a specific condition. Research done to “prove” something works will be looked
on suspiciously because there is a clear demonstration of bias.
Furthermore, chiropractic must be viewed as a profession, not a
procedure. It is important to be aware of the philosophic assumptions underlying conceptions of reality and truth but not confuse them with the search for scientific truths, which are never
absolute but remain forever tentative and approximate.31 The
traditional language of the philosophy of chiropractic might be
revised to more closely coincide with the current language in the
biologic and life sciences without loss of appropriate philosophic
meaning.32
Chiropractic Education
Although organized medicine rejected chiropractic from its outset,
occurrences within medicine had a major effect on the development of the chiropractic profession. The Flexner Report, released
in 1910, had a profound effect on chiropractic education.33 This
report was highly critical of the status of medical education in the
United States. It recommended that medical colleges affiliate with
universities to gain educational support. As Beideman has noted,
it took the chiropractic profession nearly 15 years from the time
of that report to begin the same types of changes that medicine
underwent to improve its education.34
The changes were not long in coming, however, once their
need was recognized. These improvements ultimately led to the
creation of the Council on Chiropractic Education (CCE), which
later was recognized by the U.S. Department of Education (then
the Department of Health, Education and Welfare) as the accrediting agency for the chiropractic profession.
By the late 1960s, the CCE had required its accredited institutions to use a 2-year preprofessional educational experience as a
requirement for matriculation. In 1968, the doctor of chiropractic
(DC) degree became a recognized professional degree, and in 1971
the CCE became an autonomous body. In addition to national
accreditation by CCE and the U.S. Department of Education,
regional accrediting bodies have reviewed chiropractic college programs, and all but two of the programs within the United States have
achieved accreditation. The self-evaluation and accreditation process allowed chiropractic institutions to upgrade their professional
5
standards to an unprecedented degree. The requirements of the
CCE govern the entire educational spectrum of chiropractic education, mandating that certain information must be imparted to
the student body and providing a way to monitor compliance and
to provide guidance to an individual college. The effect has been
salubrious. Today, all CCE-accredited institutions require a minimum of 3 years of college credits (90 semester hours and 134
quarter hours) for matriculation. Prerequisite coursework includes
24 semester hours in basic sciences, including biology, chemistry,
and physics, and 24 semester hours in humanities and social science. Included in the entrance requirements are 1 year of biology,
general chemistry, organic chemistry, and physics.
All CCE-accredited institutions teach a comprehensive program incorporating elements of basic science (e.g., physiology,
anatomy, and biochemistry), clinical science (e.g., laboratory diagnosis, radiographic diagnosis, orthopedics, neurology, and nutrition), and clinical intern experience. The chiropractic educational
program is a minimum of 4 years, totaling an average of 4800
classroom hours. The first and second years are devoted primarily to basic sciences, chiropractic principles, and technique skill
development. The third year emphasizes clinical and chiropractic
sciences and prepares students for the transition into their fourth
year and practical clinical experience treating the public in the college clinics. Government inquiries and comparative evaluations
have determined that the coursework and hours of instruction in
the basic sciences are very similar between chiropractic and medical schools. Chiropractic students on average spend more hours
in anatomy and physiology and fewer hours in public health. In
the clinical arena chiropractic students have very limited training in pharmacology and critical care, but have significantly more
training in clinical biomechanics, NMS diagnosis, manual therapy,
and exercise rehabilitation.
For the process of accreditation, the CCE established specific
standards with which a chiropractic educational institution must
comply to achieve and maintain accreditation.35 Care has been
taken to ensure that accreditation requirements are consistent
with the realities of sound planning practices in the DC program.
The word requirements signifies a set of conditions that must be
met for CCE accreditation to be awarded. In recognition of their
potential uniqueness, each program may be given some latitude
in the means by which they meet some requirements. However,
compliance with all requirements must be fulfilled by each accredited entity.
Although standardization of curriculum created an environment that ensures the public that most graduates of CCE institutions have been provided a competent education, each college
does not necessarily teach its students the same scope of chiropractic manipulative techniques. Educational and philosophic differences between schools can dramatically affect the curriculum and
the range of diagnostic and therapeutic procedures taught at each
college. The result is different products and practice approaches
among graduates of different schools. The major distinction
between college programs rests with those that ascribe to evidencebased education and those that rely on joint “subluxation-based”
or “philosophy-based” education.
Each institution must teach its students to adjust, but the procedures and intent taught at one college may differ from those
6
| Chiropractic Technique
taught at other institutions. Although all these forms of chiropractic adjustive techniques have many elements in common, their
approaches may differ substantially. A graduate of one college may
find it difficult to share information with the graduate of a different college that teaches some alternate form of an adjustive procedure. Furthermore, a plethora of techniques is available in the
form of postgraduate seminars, many of which are not governed
by a regulatory body or accrediting procedure that would ensure
an adequate scholastic level or competence.
Interested and probing chiropractors who noticed regularity in
their results and began to ask why those results occurred founded
the majority of chiropractic technique systems. This was largely a
“bootstrapping” effort; the impetus to gain new knowledge and
then disseminate it was largely self-driven. These approaches typically developed into systems of diagnosis and treatment (“system
techniques”). These early commendable efforts are limited by the
fact that they are often based on a biologically questionable or singular and simplistic rationale with little or absent systematic clinical
research investigation. The human body is a very complex and integrated organism, and to rely on a single evaluative or treatment procedure without substantiated clinical justification is not considered
sound clinical practice. This text hopes to improve the educational
environment by providing a foundation of fundamental standards
and psychomotor skills that are common to all adjustive thrust techniques. A list of most of the named chiropractic techniques is provided in Appendix 1, and many forms of chiropractic technique
systems are described in the book, Technique Systems in Chiropractic
by Robert Cooperstein and Brian Gleberzon (Elsevier 2004).
Chiropractic education continues to be innovative and to advance,
as demonstrated by the growing adoption of evidence-based practice
(EBP) content into chiropractic education. In 1999 the National
Center for Complementary and Alternative Medicine (NCCAM)
established an R25 Education Project Grant Program to encourage expanded knowledge of complementary and alternative medicine (CAM) in medical education. The initial round of funding was
focused on medical schools and required them to pair with CAM
professions in the development of medical curricula that would
increase CAM literacy in medical school graduates and residents.
Beginning in 2005 a new round of NCCAM R25 educational grants was announced. This round of funding, the CAM
Practitioner Research Education Project Grant Partnership, was
focused on CAM health care institutions and on increasing the
quality and quantity of evidence-based clinical research content
in their curricula. The grant required that CAM institutions pair
with a research-intensive institution with the goal of improving
CAM students’ EBP skills. In the first round of funding, five institutions were awarded partnership grants. Two of the originally
funded institutions were chiropractic colleges (National University
of Health Sciences and Western States Chiropractic College) and
subsequent rounds of funding have awarded to grants to two additional chiropractic institutions (Northwestern Health Sciences
University and Palmer Chiropractic College).
clinical science subjects, part III is a written clinical competency
examination, and part IV is a practical objective structured competency examination, which tests candidates on x-ray interpretation and diagnosis, chiropractic technique, and case management.
In addition to the national boards, most states require candidates
to take a jurisprudence examination covering that state’s practice
act and administrative rules.
Today, chiropractic is approved under federal law in all 50
states, in the Canadian provinces, and in a majority of foreign
countries. Chiropractic practice in the United States is regulated
by state statute and by each state’s board of chiropractic examiners. Chiropractic practice acts define the practice of chiropractic locally and establish regulations for licensure, discipline, and
scope of practice for all 60 jurisdictions in North America.
There is significant variation and diversity of definitions in
state practice acts and the interpretation of what constitutes each
state’s practice act and scope of practice are profound and bewildering.36 This diversity and variability undermine the desire of
many chiropractors to be regarded as a unified profession with
clearly established standards of practice and treatment.37 A survey
of practice acts revealed a broad scope of chiropractic practices,
but also demonstrated a lack of consensus within the profession,
which causes confusion for the profession itself, for those seeking
services from the profession, and for those who conduct business
with members of the profession.38
Licensure
Chiropractic is the largest CAM profession with approximately
60,000 practitioners, and the most widely used CAM profession
(30% of annual CAM visits). Approximately 11% of the population uses chiropractic services each year, and it is estimated that
To become licensed, practitioners must pass four national board
examinations. Part I tests basic science knowledge, part II evaluates
Scope of Practice
Chiropractors are licensed as primary contact portal of entry providers in all 50 states. They are trained to triage, differentially diagnose, and refer nonchiropractic cases. Chiropractors use standard
physical examination procedures with an emphasis on orthopedic,
neurologic, and manual examination procedures. Chiropractors
are licensed to take x-rays in all 50 states and, when indicated,
can order special tests if permitted by state law (e.g., blood work,
imaging).
Although there is wide variation in therapeutic scope of practice from state to state, nearly all chiropractors use a variety of
manual therapies with an emphasis on specific adjustive techniques. Therapeutic alternatives range from manual therapy, physical therapy, and spinal adjustments to exercise and nutritional
and dietary counseling.
Chiropractors view themselves as specialists in NMS care but
also as complementary and alternative caregivers for a number of
other chronic conditions. In these situations chiropractors typically incorporate other therapeutic intervention such as counseling on diet, nutrition, and lifestyle modification. Management or
comanagement of patients with hypertension, diabetes, or dyslipidemia are a few examples.
Patient Access and Chiropractic
Utilization
Chapter 1â•… General Overview of the Chiropractic Profession |
one third of the population has seen a chiropractor at some point
in their lifetimes. Nearly all chiropractors surveyed (98%) state
that they refer patients to medical doctors, and a North Carolina
study indicates 65% of medical doctors have referred to a chiropractor at some point in their career. A majority of chiropractors (77%) state they have had a referral from a medical doctor.
Insurance coverage for chiropractic is quite extensive. Chiropractic
is included under Medicare and Medicaid laws with worker’s compensation coverage in all 50 states. Approximately 50% of health
maintenance and 75% of private health insurance plans cover
chiropractic.
Recent legislation has greatly expanded chiropractic services
in the Department of Defense and Veterans Administration (VA)
health care programs. This legislation was prompted by an independent demonstration project funded by the U.S. Department
of Defense on Chiropractic Health Care. This project produced
data confirming the cost-effectiveness of chiropractic services,
with patients reporting chiropractic care to be as good as or better than medical care for selected musculoskeletal conditions. In
late 2001, the U.S. Congress enacted a bill to provide chiropractic
services for the military on a comprehensive and permanent basis.
Chiropractic services are in the process of being established in all
communities in the United States and worldwide where there are
active U.S. military personnel.
A report from the Veterans Health Administration Office of
Public Health and Occupational Hazards cites musculoskeletal
injuries as the number-one complaint (41.7%) among U.S. veterans of Iraq and Afghanistan.39 By working in concert with medical
doctors and other health care providers at VA facilities, chiropractors could have an influence on the upsurge of joint and back pain
among U.S. veterans.
Chiropractic access to hospital services has expanded during
the last several decades. This expansion was initiated by the successful outcome of a long antitrust case that the profession waged
against organized medicine. The outcome of the Wilk trial on
February 7, 1990, in the Seventh Circuit U.S. Court of Appeals
found the American Medical Association (AMA) guilty of an illegal conspiracy to destroy the competitive profession of chiropractic. This decision arose from a suit brought by five chiropractors
alleging that the AMA, along with several other organizations
involved in health care, conspired to restrain the practice of chiropractic through a sustained and unlawful boycott of the chiropractic profession. This was despite the fact that chiropractic care
had been found to be, in some cases, as effective or more effective
in treating certain NMS-related health problems.
Although opposition to inclusion of chiropractic was initially
profound, it has been gradually waning. Staff privileges are being
sought and gained by more and more chiropractors.
Use of CAM services has increased dramatically during the last
several decades.40,41 “Recent estimates based on the 2002 National
Health Interview Survey reveal that 62.1% of U.S. adults used
CAM therapies during the previous year.”42 Within the CAM
community, chiropractic accounts for the largest provider group
and the greatest number of patient visits.40,41 The growing evidence base and expanding demand for CAM services has stimulated the medical community to recognize that CAM literacy
should be an essential part of medical education. Surveys have
7
indicated that an overwhelming percentage of medical college
faculty and students want information about CAM and integrative therapy in their school’s curriculum.42 More recent surveys
indicated that the amount of time devoted to CAM education has
increased and that medical students are more confident in their
understanding and ability to counsel patients about CAM therapies.42 The number of prestigious medical universities interested
in integrative and CAM therapies has increased dramatically during the preceding 5 years, with membership in the Consortium
of Academic Health Centers for Integrative Medicine increasing
from 11 to 39 schools.42
Research
Federal recognition and funding increased dramatically during the
1990s, with a number of institutions receiving federally funded
grants and monies allocated for the development of a research
center and annually funded research workshops. The National
Workshop for Developing the Chiropractic Research Agenda (or
Research Agenda Conference) occurred in the summer of 1996.
Five specific areas of chiropractic research were examined: clinical
research, basic research, educational research, outcomes research,
and health services research. For each topic area, a group of specialists met to develop specific recommendations. Barriers to research
and opportunities for research were discussed at length; obviously,
one desire of the attendees was to find ways to overcome those
identified barriers. The proceedings have been published. A continuation grant from the Health Resource Service Administration
was approved for the program coordinators, ensuring that this
work would move forward into the future.
Opportunities for funding chiropractic research expanded in
1998 when congress established the NCCAM at the National
Institutes of Health (NIH). The centers were designed to stimulate, develop, and support research on CAM for the benefit
of the public. Complementary and alternative health care and
medical practices are those health care and medical practices
that are not currently an integral part of conventional medicine.
The list of procedures that are considered CAM changes continually as CAM practices and therapies that are proven safe and
effective become accepted as “mainstream” health care practices.
NCCAM has the roles of exploring CAM healing practices in
the context of rigorous science, training CAM researchers, and
disseminating authoritative information. Funding is made available through the NIH, and grants have been awarded to chiropractic institutions.
In 2006 a group of the profession’s leading researchers undertook a comprehensive decade review of the research accomplishments and status of chiropractic research. They concluded,
“During the past decade, the work of chiropractic researchers has
contributed substantially to the amount and quality of the evidence for or against spinal manipulation in the management of
low back pain, neck pain, headache, and other conditions.”43
They recommended that the profession and its education
institutions should strengthen its efforts to promote chiropractic
research, with a focus on translating research findings into practice
and a focus on evidence-based health care and best practices and
their dissemination.
8
| Chiropractic Technique
Standard of Care and Guidelines
In early 1990, the profession held its first Consensus Conference
on the validation of chiropractic methods and standard of care.44
The conference brought together researchers, academicians, technique developers, politicians, and others from all walks of chiropractic life to develop systems to assess the validity of chiropractic
procedures. The program addressed a variety of topics related to
technique validation, followed by several roundtable and panel
discussions related to the way such validation might occur.
The first major chiropractic-sponsored critical assessment of
chiropractic methods was the professionally commissioned 1992
RAND report.45 This project was designed to look at the clinical
criteria for the use of spinal manipulation for low back pain as
delivered by both chiropractors and medical doctors. The project
involved four stages of study: one to review the literature concerning manipulation and low back pain, a second to convene a panel
of back pain experts from a variety of disciplines to rate the appropriateness of a number of indications for the use of manipulation
in treating low back pain, a third to convene a second panel solely
composed of chiropractors to rate those same indications, and a
fourth to analyze the services of practicing chiropractors.46
The expert panels found that there was clear support for the use
of spinal manipulation in treating acute low back pain of mechanical origin with no signs of nerve root involvement. Conclusions
of the fourth stage were that the proportion of chiropractic spinal manipulation was judged congruent with appropriateness
criteria similar to proportions previously described for medical
procedures.46
A similar project with parallel results examined the appropriateness of manipulation of the cervical spine.47,48 The effect of the
studies rests with the importance of a multidisciplinary panel of
experts being able to determine that spinal manipulation is appropriate for specific clinical problems of the lumbar and cervical
spine.
Another consensus process, the Mercy Conference,49 so-called
because it occurred at the Mercy Center in California, was a consensus conference that brought together chiropractic clinical
experts to look at the issue of standards of practice. This conference
began the arduous task of looking at the full range of chiropractic
procedures, diagnostic as well as clinical. The two questions that
needed to be asked were, Are there any scientific data to support
a conclusion about the use of a test or a procedure, and In the
absence of such data, was there a consensus of opinion on the use
of that test or procedure?
A list of the chapters in the published proceedings gives an idea
of the scope of coverage of this conference and the guidelines it
produced:
• History and physical examination
• Diagnostic imaging
• Instrumentation
• Clinical laboratory
• Record keeping and patient consents
• Clinical impressions
• Modes of care
• Frequency and duration of care
• Reassessment
•
•
•
•
•
Outcome assessment
Collaborative care
Contraindications and complications
Preventive and maintenance care and public health
Professional development
Although not without great controversy, this conference had a significant effect on professional practice patterns. In an effort to maintain
the momentum generated by the Mercy Conference and generate
current and equitable evidence-based guidelines, the Council on
Chiropractic Guidelines and Practice Parameters (CCGPP) was
formed in 1995. CCGPP was delegated to examine all existing
guidelines, parameters, protocols, and best practices in the United
States and other nations in the construction of this document.
CCGPP researches and rates evidence that is compiled in a
summary document for the chiropractic profession and other
related stakeholders. The information contained in the eight clinical chapters covered in this project is being assembled by CCGPP
as a literature synthesis. Appropriate therapeutic approaches will
consider the literature synthesis as well as clinical experience, coupled with patient preferences in determining the most appropriate
course of care for a specific patient. After several years of work the
CCGPP research teams have completed a number of chapters and
have posted them on the Internet for comment.
The 1990s also produced two additional and significant independent analyses concerning the management of back pain—the
Manga report and the Agency for Health Care Policy and Research
(now the Agency for Healthcare Research and Quality – AHRQ)
Guidelines for Acute Low Back Problems in Adults.50 Both had very
positive implications for chiropractic care.
The Manga report51 examined the effectiveness and cost�effectiveness of chiropractic management for low back pain in
the province of Ontario. Perhaps of greatest interest to the profession was the first executive finding: “On the evidence, particularly
the most scientifically valid clinical studies, spinal manipulation
applied by chiropractors is shown to be more effective than alternative treatments for LBP [low back pain].” They further concluded that chiropractic manipulation was safe and “far safer than
medical management of LBP.” Chiropractic care was determined
to be more cost-effective than medical care.
The authors concluded that increased use of chiropractic services
would lead to a significant reduction in costs, fewer hospitalizations, and reduced chronic disability. Ultimately, recommendations were made to fully insure chiropractic services under the
Ontario Health Insurance Plan, to extend hospital privileges, and
to increase funding for chiropractic research and education.
In a follow-up study, Manga and Angus concluded that “there
is an overwhelming body of evidence indicating that chiropractic
management of low back pain is more cost-effective than medical
management” and that “there would be highly significant cost savings if more management of low back pain was transferred from
physicians to chiropractors.”52
AHRQ published its guideline number 14, which discusses
the management of low back pain.50 This document represents a
synthesis of the best evidence regarding the assessment and management of acute low back pain in the adult population of the
United States. It employed a panel of experts drawn from the
professions involved in treating low back pain, and this certainly
Chapter 1â•… General Overview of the Chiropractic Profession |
included chiropractic involvement. There were a number of
principal conclusions:
• The initial assessment of patients with acute low back problems focuses on the detection of “red flags.”
• In the absence of red flags, imaging studies and other testing
of the patient are usually not helpful during the first 4 weeks
of low back pain.
• Most notably for the chiropractic profession, relief of discomfort can be accomplished most safely with nonprescription medication or spinal manipulation.
• Bed rest in excess of 4 days is not helpful and may be harmful to the patient.
• Patients need to be encouraged to return to work as soon as
possible.
• Patients suffering from sciatica recover more slowly, but further evaluation can be delayed; furthermore, 80% of patients
with sciatica recover without the need for surgery.
A 4-year study of comprehensive data from 1.7 million members of a managed care network in California identified that
access to managed chiropractic care may reduce overall health
care expenditures through several effects, including “(1) positive
risk selection; (2) substitution of chiropractic care for traditional
medical care, particularly for spine conditions; (3) more conservative, less invasive treatment profiles; and (4) lower health service
costs associated with managed chiropractic care. Systematic access
to managed chiropractic care not only may prove to be clinically
beneficial but also may reduce overall health care costs.”53
THE FUTURE
The chiropractic profession has labored long and hard to get to
where it is, and the future holds exciting opportunities and challenges. First among its challenges is reaching consensus concerning its scope of practice and professional identity. Practitioners
need to determine if they wish to continue to be viewed primarily as back pain specialists or expand the perception of chiropractic patient management skills to include such arenas as extremity
disorders, sports medicine, functional medicine, and diet and
nutritional counseling.
It is clear to the authors that the profession has the foundations, capacity, and expertise to expand the public’s perception
and awareness of its more extensive skill set, especially in the arena
of extremity dysfunction and disorders. An expanded professional
image can only be accomplished through professional consensus.
For this to occur, the profession must move beyond petty philosophic differences and work toward clinically demonstrating that
its graduates and practitioners can safely and effectively treat a
wide variety of health care disorders.
Chiropractors must provide a consistent brand and quality
of care wherever it is delivered. The Association of Chiropractic
Colleges “Paradigm of Chiropractic,” adopted by the profession
internationally at the World Federation of Chiropractic’s Paris
Congress in 2001, contains principles and goals. The “Paradigm”
emphasizes an approach to the health and well-being of patients
by adjustment and manipulation to address vertebral subluxation
and joint dysfunction and the effect of spinal problems on biomechanical and neurologic integrity and health.54
9
For a perspective from outside the profession, Wardwell,9 a
noted chiropractic scholar and sociologist, has offered five possible outcomes for the chiropractic profession. The first option
envisions the chiropractic profession disappearing altogether,
with other professions (e.g., physical therapy and medicine) providing manual therapy. A second outcome for chiropractic places
the profession in an ancillary position to medicine in a status
similar to the role physical therapy provides today. Third, chiropractic could follow the path of osteopathy toward fusion with
medicine. In a fourth possibility, the profession could evolve to a
limited medical status comparable to dentistry, podiatry, optometry, or psychology. Finally, the profession may simply remain
in the position it occupies today, a position of increasing recognition and public acceptance and use, but outside mainstream
medical care.
Wardwell9 favors the fourth scenario, in which chiropractic evolves into a limited medical profession specializing in
the treatment of musculoskeletal disorders. This should place
the profession as an accepted member of the health care
team, cooperating with medicine rather than in an adversarial
position.55
Although the profession faces some significant challenges and
competition for its services, it appears unlikely that the profession will be supplanted by physical therapy or follow the path
of osteopathy into medical absorption. Whether chiropractic
will eventually become a limited medical profession is for the
future to tell, but this also seems unlikely based on the public’s
increased use of chiropractic and other CAM professions and
therapies.
The chiropractic profession has survived its first century
against great odds and seems destined to grow as it receives
increasing acceptance from the public and the health care community. However, along with increased awareness and acceptance comes increased scrutiny. The future holds the chance for
opportunity and advancement and the chance to lose some hardgained privileges. To ensure a bright future, the profession needs
to remain committed to critical self-evaluation and investigation
while placing the needs of the patient above its own economic
self-interests.
A challenge for the future is to classify and place all chiropractic techniques into a framework that allows the profession to
determine which ones have a basis in fact. Such work has indeed
begun.44-49 The profession can then begin to weed out unacceptable procedures that are promoted largely on the strength of the
cult of personality that surrounds the founder of the system. The
profession can appreciate the effort and drive that led so many
chiropractic pioneers to devise their systems, but to allow those
systems to flourish solely because of those efforts is to do a grave
disservice to those who follow. Serious investigation into many of
these systems is underway.
The techniques in this book are not those of any particular
system, but represent a collection of procedures from many
different systems, thus providing information about adjusting a
wide range of areas in the body. Taken as a whole, they are a fair
cross-representation of what the chiropractic profession has to
offer. This book represents but one effort to ensure that credible,
rational methods of chiropractic technique are available.
10
| Chiropractic Technique
CONCLUSIONS
The science of chiropractic is moving forward in the investigation of the art of chiropractic. The need to continue and expand
scientific research is paramount to maintaining chiropractic practice rights. The process initiated by the profession’s consensus conferences, research efforts, and standard of care clinical guidelines
development must be ongoing. Phillips would posit that scientific
inquiry in chiropractic has created a “new soul” that is willing to
search for truth, to challenge the “status quo” in the hope of making it better, and to be self-reflective of its internal values.56
The chiropractic profession is rapidly gaining acceptance.
It now has a body of credible research supporting significant
elements of its patient care. The profession’s research capacity and clinical research literature have expanded significantly.
Several fine scientific journals (at least one of which is indexed
worldwide) exist and the profession has an increasing number of
high-quality textbooks. The early signs of incorporating an EBP
approach to patient management are emerging. An increasing
number of chiropractic colleges have been awarded EBP curriculum development grants, and most chiropractic colleges promote and support the inclusion of EBP within their curricula
and patient clinics. A number of postgraduate offerings in EBP
are available, and chiropractic EBP resources are available and
expanding.
Meeker and Haldeman57 have noted, despite some major health
care advances during the preceding 20 years, that the chiropractic profession is still in a “transitional phase” with its future role
in the overall health care system remaining unclear. They suggest
that this is because the profession has yet to resolve “questions of
professional and social identity.”57
Whatever identity members of the profession might prefer, any
effective identity chosen must reflect not only chiropractic education, competencies, and legal scope of practice, but also the realities and dictates of the health care marketplace. At this time it
appears that the majority of the general public perceives the profession as a specialist for back pain much as a dentist is viewed as
a specialist for teeth.
In some countries such as Canada, Denmark, and the United
Kingdom, that process has advanced significantly. A number of chiropractic schools outside the United States have affiliated with universities, and chiropractic services are covered within the national
health care systems in a number of these countries. The identity
of chiropractic in these markets is evolving into a limited-practice
model focused on expertise, evaluation, and treatment of a narrow
range of musculoskeletal disorders, especially spinal problems.58
In a survey conducted at the Institute of Social Research at
Ohio Northern University, important issues for the chiropractic
profession were addressed including the appropriateness of various services, attitudes toward prescription drugs and immunization, and opinions on whether specific or general visceral health
problems may be related to subluxation or its correction.59 The
results of the survey found that the North American chiropractic profession has largely outgrown its historical stereotype of
being defensive, divided, and isolated from mainstream health
care. The survey concluded that “North American chiropractors
are less defensive, less absolutist and less polemic than the stereotype. The data also indicate that chiropractors know they offer
patients a valuable service. The picture emerging from their survey is of a confident, pragmatic and discerning profession, more
capable than ever of participating in an interdisciplinary health
care environment.”59
c0010
Joint Anatomy and Basic
Biomechanics
Outline
FUNDAMENTAL CONCEPTS,
PRINCIPLES, AND TERMS
Levers
Body Planes
Axes of Movement
Joint Motion
Synovial Joints
Bony Elements
Articular Cartilage
11
11
12
13
13
15
15
16
Fibrocartilage
Ligamentous Elements
Synovial Fluid
Articular Neurology
JOINT FUNCTION
MECHANICAL FORCES ACTING ON
CONNECTIVE TISSUE
Tension Forces
Compression Forces
Shear Forces
T
his chapter provides an academic picture of the applied
anatomy and clinical biomechanics of the musculoskeletal
system. The human body may be viewed as a machine
formed of many different parts that allow motion. These motions
occur at the many joints formed by the specific parts that compose
the body’s musculoskeletal system. Although there is some controversy and speculation among those who study these complex
activities, the information presented here is considered essential
for understanding clinical correlations and applications. Clinical
biomechanics and applied anatomy encompass the body of knowledge that employs mechanical facts, concepts, principles, terms,
methodologies, and mathematics to interpret and analyze normal and abnormal human anatomy and physiology. Discussions
of these concepts require specific nomenclature, which enables
people working in a wide variety of disciplines to communicate
(see glossary). Biomechanics is often overwhelming because of its
mathematical and engineering emphasis. This chapter presents a
nonmathematical approach to defining clinically useful biomechanical concepts necessary to describe and interpret changes in
joint function. Thorough explanations of biomechanical concepts
are discussed in other works.1-3
FUNDAMENTAL CONCEPTS, PRINCIPLES,
AND TERMS
Mechanics is the study of forces and their effects. Biomechanics is
the application of mechanical laws to living structures, specifically
to the locomotor system of the human body. Therefore biomechanics concerns the interrelations of the skeleton, muscles, and
joints. The bones form the levers, the ligaments surrounding the
joints form hinges, and the muscles provide the forces for moving
the levers about the joints. Force is an action exerted on a body that
causes it to deform or to move. The most important forces involved
with musculoskeletal levers are those produced by �muscle, gravity,
and physical contacts within the environment.
Kinematics is a branch of mechanics that deals with the geometry of the motion of objects, including displacement, velocity, and
acceleration, without taking into account the forces that �produce
16
17
17
18
20
23
24
24
24
Chapter
2
Torque Forces
Newton’s Laws of Motion
PROPERTIES OF CONNECTIVE
TISSUE
Muscle
Ligaments
Facet Joints
Intervertebral Discs
MODELS OF SPINE FUNCTION
25
25
26
27
28
29
30
33
the motion. Kinetics, however, is the study of the relationships
between the force system acting on a body and the changes it
produces in body motion.
Knowledge of joint mechanics and structure, as well as the
effects that forces produce on the body, has important implications for the use of manipulative procedures and, specifically, chiropractic adjustments. Forces have vector characteristics whereby
specific directions are delineated at the points of application.
Moreover, forces can vary in magnitude, which affects the acceleration of the object to which the force is applied.
Levers
A lever is a rigid bar that pivots about a fixed point, called the
axis or fulcrum, when a force is applied to it. A force in the body
is applied by muscles at some point along a lever to move a body
part to overcome some form of resistance. The lever is one of the
simplest of all mechanical devices that can be called a machine. The
relationship of fulcrum to force and to resistance distinguishes the
different classes of levers.
In a first-class lever, the axis (fulcrum) is located between
the force and resistance; in a second-class lever, the resistance is
between the axis and the force; and in a third-class lever, the force
is between the axis and the resistance (Figure 2-1). Every movable
bone in the body acts alone or in combination, forcing a network
of lever systems characteristic of first- and third-class levers. There
are virtually no second-class levers in the body, although opening
the mouth against resistance is an example.
With a first-class lever, the longer the lever arm, the less force
required to overcome the resistance. The force arm may€be �longer,
shorter, or equal to the resistance arm, but the axis is always
between these two points. An example of a first-class lever in the
human body is the forearm moving from a position of flexion
into extension at the elbow through contraction of the triceps
muscle.
Third-class levers are the most common types in the body
because they allow the muscle to be inserted near the joint and can
thereby produce increased speed of movement, although at a sacrifice of force. The force must be smaller than the resistance arm,
11
12
| Chiropractic Technique
Force
Resistance
Fulcrum
A
R
F
A
F
F
R
R
B
F
R
C
A
F
F
R
R
F
A
A
D
R
Figure 2-1â•… A, Lever system showing components. B, First-class lever system. C, Second-class lever system. D, Third-class lever system. A, Axis
(fulcrum); F, force; R, resistance.
and the applied force lies closer to the axis than the resistance force.
An example of a third-class lever is flexion of the elbow joint
through contraction of the biceps muscle.
Body Planes
It is also necessary to delineate the specific body planes of reference, because they are used to describe structural position and
directions of functional movement. The standard position of
reference, or anatomic position, has the body facing forward, the
hands at the sides of the body, with the palms facing forward,
and the feet pointing straight ahead. The body planes are derived
from dimensions in space and are oriented at right angles to one
another. The sagittal plane is vertical and extends from front to
back, or from anterior to posterior. Its name is derived from the
direction of the human sagittal suture in the cranium. The median
sagittal plane, also called the midsagittal plane, divides the body
into right and left halves (Figure 2-2, A, Table 2-1). The coronal
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
13
Y
Translation
Z
Rotation
A
C
B
X
Figure 2-2â•… A, Midsagittal plane. Movements of flexion and exten-
sion take place about an axis in the sagittal plane. B, Coronal plane.
Movements of abduction and adduction (lateral flexion) take place about
an axis in the coronal plane. C, Transverse plane. Movements of medial
and lateral rotation take place about an axis in the transverse plane.
TABLE 2-1
Figure 2-3â•… Three-dimensional coordinate system identifying the
translational and rotational movements along or around the three axes to
produce 6 degrees of freedom.
Body Planes of Movement
Plane of Movement
Axis
Joint Movement
Sagittal
x
Coronal
z
Transverse
y
Flexion and extension; Lateral to Medial,
and Medial to Lateral Glide
Abduction and adduction (lateral flexion);
Anterior to Posterior, and Posterior to
Anterior Glide
Medial and lateral rotation (axial rotation)
Inferior to Superior, and Superior to
Inferior Glide (compression, distraction)
plane is vertical and extends from side to side. Its name is derived
from the orientation of the human coronal suture of the cranium.
It may also be referred to as the frontal plane, and it divides the
body into anterior and posterior components (Figure 2-2B). The
transverse plane is a horizontal plane and divides a structure into
upper and lower components (Figure 2-2C).
translational. Curvilinear motion occurs when a translational
movement accompanies rotational movements. The load that produces a rotational movement is called torque; a force that produces
a translational movement is called an axial or shear force.
Axes of Movement
Motion can be defined as a continuous change in position of an
object and can be described as rotational, translational or curvilinear. Rotational motion takes place around an axis. Translational
movements are linear movements or, simply, movement in a straight
line. The terms slide and glide have been used to refer to translational movements between joint surfaces. Curvilinear motion combines both rotational and translational movements and is the most
common motion produced by the joints of the body (Figure 2-4).
The three axes of motion (x, y, and z) are formed by the junction
of two planes. The x-axis is formed by the junction of the coronal
and transverse planes. The y-axis is formed by the �junction of the
An axis is a line around which motion occurs. Axes are related
to planes of reference, and the cardinal axes are oriented at right
angles to one another. This is expressed as a three-dimensional
coordinate system with X, Y, and Z used to mark the axes (Figure
2-3). The significance of this coordinate system is in defining
or locating the extent of the types of movement possible at each
joint—rotation, translation, and curvilinear motion. All movements that occur about an axis are considered rotational, whereas
linear movements along an axis and through a plane are called
Joint Motion
14
| Chiropractic Technique
A
A
A
A
B
B
B
Instantaneous
axis of rotation
B
A
B
Figure 2-4â•… A, Translational movement. B, Curvilinear movement: a combination of translation and rotation movements.
A
B
C
Figure 2-5â•… A, Sagittal plane movement of flexion. B, Coronal plane movement of lateral flexion. C, Transverse plane movement of axial rotation.
coronal and sagittal planes. The z-axis is formed by the junction
of the sagittal and transverse planes. The potential exists for each
joint to exhibit three translational movements and three rotational
movements, constituting 6 degrees of freedom. The axis around or
along which movement takes place and the plane through which
movement occurs define specific motions or resultant positions.
The x-axis extends from one side of the body to the other. The
motions of flexion and extension occur about this axis and through
the€sagittal plane. Flexion is motion in the anterior direction for joints
of the head, neck, trunk, upper extremity, and hips. Flexion of the knee,
ankle, foot, and toes is movement in the posterior direction. Extension
is motion in the direct opposite manner from flexion (Figure 2-5,
A). Lateral to medial glide and medial to lateral glide (laterolisthesis)
translate through the coronal plane and along the x-axis.
The z-axis extends horizontally from anterior to posterior.
Movements of abduction and adduction of the extremities, as
well as lateral flexion of the spine, occur around this axis and
through the coronal plane. Lateral flexion is a rotational movement and is used to denote lateral movements of the head, neck,
and trunk in the coronal plane (see Figure 2-5, B). In the human,
lateral flexion is usually combined with some element of rotation. Abduction and adduction are also motions in a coronal
plane. Abduction is movement away from the body, and adduction is movement toward the body; the reference here is to the
midsagittal plane of the body. This would be true for all parts
of the extremities, excluding the thumb, fingers, and toes. For
these structures, reference points are found within that particular
extremity. Anterior to posterior glide (anterolisthesis) and posterior to anterior glide (retrolisthesis) are translational movements
through the sagittal plane and along the z-axis.
The longitudinal axis (y-axis) is vertical, extending in a headto-toe direction. Movements of medial (internal) and lateral
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
(external) rotation in the extremities, as well as axial rotation in
the spine, occur around it and through the transverse plane. Axial
rotation is used to describe this type of movement for all areas of
the body except the scapula and clavicle. Rotation occurs about
an anatomic axis, except in the case of the femur, which rotates
around a mechanical axis.4 In the human extremity, the anterior
surface of the extremity is used as a reference area. Rotation of the
anterior surface toward the midsagittal plane of the body is medial
(internal) rotation, and rotation away from the midsagittal plane
is lateral (external) rotation (see Figure 2-5, C ). Supination and
pronation are rotation movements of the forearm. Distraction and
compression (altered interosseous spacing or superior or inferior
glide) translate through the transverse plane along the y-axis.
Because the head, neck, thorax, and pelvis rotate about longitudinal axes in the midsagittal area, rotation cannot be named
in reference to the midsagittal plane. Rotation of the head, spine,
and pelvis is described as rotation of the anterior surface posteriorly toward the right or left. Rotation of the scapula is movement
about a sagittal axis, rather than about a longitudinal axis. The
terms clockwise or counterclockwise are used.
The extent of each movement is based more or less on the joint
anatomy and, specifically, the plane of the joint surface. This is
especially important in the spinal joints. Each articulation in the
body should then exhibit, to some degree, flexion, extension, right
and left lateral flexion, right and left axial rotation, anteroposterior
glide, posteroanterior glide, lateromedial glide, mediolateral glide,
compression, and distraction.
Joints are classified first by their functional capabilities
and then are subdivided by their structural characteristics.
Synarthroses allow very little, if any, movement; an amphiarthrodial (symphysis) joint allows motion by virtue of its structural
components; diarthroses, or true synovial joints, allow significant movement. The structural characteristics of these joints are
detailed in Table 2-2.
TABLE 2-2
Synovial Joints
Synovial joints are the most common joints of the human appendicular skeleton, representing highly evolved, movable joints.
Although these joints are considered freely movable, the degree
of possible motion varies according to the individual structural
design, facet planes, and primary function (motion vs. stability).
The components of a typical synovial joint include the bony
elements, articular cartilage, fibrocartilage, synovial membrane,
fibroligamentous joint capsule, and articular joint receptors. An
understanding of the basic anatomy of a synovial joint forms the
foundation for appreciation of clinically significant changes in the
joint that lead to joint dysfunction.
Bony Elements
The bony elements provide the supporting structure that gives the
joint its capabilities and individual characteristics by forming lever
arms to which intrinsic and extrinsic forces are applied. Bone is actually a form of connective tissue that has an inorganic constituent
(lime salts). A hard outer shell of cortical bone provides structural
support and surrounds the cancellous bone, which contains marrow
and blood vessels that provide nutrition. Trabecular patterns develop
in the cancellous bone, corresponding to mechanical stress applied
to and required by the bone (Figure 2-6). Bone also has the important role of hemopoiesis (formation of blood cells). Furthermore,
bone stores calcium and phosphorus, which it exchanges with
blood and tissue fluids. Finally, bone has the unique characteristic
of repairing itself with its own tissue as opposed to fibrous scar tissue, which all other body tissues use. Bone is a very dynamic tissue,
constantly remodeling in response to forces from physical activity
and in response to hormonal influences that regulate systemic calcium balance. Bone, by far, has the best capacity for remodeling,
repair, and regeneration of all the tissues making up joint struc-
Joint Classification
Joint Type
Synarthrotic
Fibrous
Cartilaginous
Diarthrotic
Uniaxial
Biaxial
Multiaxial
Plane (nonaxial)
15
Structure
Example
Suture—nearly no movement
Syndesmosis—some movement
Synchondrosis—temporary
Symphysis—fibrocartilage
Cranial sutures
Distal tibia-fibula
Epiphyseal plates
Pubes
Intervertebral discs
Ginglymus (hinge)
Trochoid (pivot)
Condylar
Ellipsoid
Sellar (saddle)
Triaxial
Spheroid (ball and socket)
Elbow
Atlantoaxial joint
Metacarpophalangeal joint
Radiocarpal joint
Carpometacarpal joint of the thumb
Shoulder
Hip
Intercarpal joints
Posterior facet joints in the spine
16
| Chiropractic Technique
Gliding
zone
Tangential
zone
Transitional
layer
Vertical
trabeculae
Radial
zone
Horizontal and
oblique trabeculae
Medial “compression”
trabecular system
Zone of
calcified
cartilage
Subchondral
plate
Lateral
“tension”
trabecular
system
Figure 2-6â•… Trabecular patterns corresponding to mechanical stresses
in the hip joint and vertebra. (Modified from Hertling D, Kessler RM:
Management of common musculoskeletal disorders: Physical therapy princi­
ples and methods, ed 2, Philadelphia, 1990, JB Lippincott.)
tures. The bony elements of the spine are the vertebral body and
neural arch. The cortical shell (compact bone) and cancellous core
(spongy bone) play a significant role in weight-bearing and the
absorption of compressive loads. The compressive strength of the
vertebrae increases from C1 to L5.
Articular Cartilage
Articular cartilage, a specialized form of hyaline cartilage, covers the
articulating surfaces in synovial joints and helps to transmit loads and
reduce friction. It is bonded tightly to the subchondral bone through
the zone of calcification, which is the end of bone visible on x-ray
film. The joint space visible on x-ray film is composed of the synovial
cavity and noncalcified articular cartilage. In its normal composition, articular cartilage has four histologic areas or zones (Figure 2-7).
These zones have been further studied and refined so that a wealth of
newer information regarding cartilage has developed.
The outermost layer of cartilage is known as the gliding zone,
which itself contains a superficial layer (outer) and a tangential
layer (inner). The outer segment is made up solely of collagen randomly oriented into flat bundles. The tangential layer consists of
densely packed layers of collagen, which are oriented parallel to the
surface of the joint.5 This orientation is along the lines of the joint
motion, which implies that the outer layers of collagen are stronger when forces are applied parallel to the joint motion rather than
perpendicular to it.6 This particular orientation of fibers provides
a great deal of strength to the joint in normal motion. The gliding
zone also has a role in protecting the deeper elastic cartilage.
The transitional zone lies beneath the gliding zone. It represents
an area where the orientation of the fibers begins to change
from the parallel orientation of the gliding zone to the more
Figure 2-7â•… Microscopic anatomy of articular cartilage.
perpendicular orientation of the radial zone. Therefore fiber orientation is more or less oblique and, in varying angles, formed
from glucuronic acid and N-acetylgalactosamine with a sulfate
on either the fourth or sixth position. The keratin compound
is formed with galactose and N-acetylgalactosamine. All of this
occurs in linked, repeating units (Figure 2-8).
Articular cartilage is considered mostly avascular and lacks a
perichondrium, eliminating a source of fibroblastic cells for repair.
Articular cartilage must rely on other sources for nutrition, removal
of waste products, and the process of repair. Therefore intermittent compression (loading) and distraction (unloading) are necessary for adequate exchange of nutrients and waste products. The
highly vascularized synovium is believed to be a critical source of
nutrition for the articular cartilage it covers. The avascular nature
of articular cartilage limits the potential for cartilage repair by
limiting the availability of the repair products on which healing
depends. Chondrocytes, the basic cells of cartilage that maintain
and synthesize the matrix, are contained within a mesh of collagen and proteoglycan that does not allow them to migrate to the
injury site from adjacent healthy cartilage.7 Moreover, the articular
cartilage matrix may contain substances that inhibit vascular and
macrophage invasion and clot formation that are also necessary
for healing.8 After an injury to the articular cartilage, the joint
can return to an asymptomatic state after the transient synovitis
subsides. Degeneration of the articular cartilage depends on the
size and depth of the lesion, the integrity of the surrounding articular surface, the age and weight of the patient, associated meniscal and ligamentous lesions, and a variety of other biomechanical
factors.7 Continuous passive motion has increased the ability
of€�full-thickness defects in articular cartilage to heal, producing
tissue that closely resembles hyaline cartilage.9
Fibrocartilage
Fibrocartilage has a higher fiber content than other types of cartilage. It has the properties of both dense irregular connective tissue
and articular cartilage. Fibrocartilage forms much of the substance
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
17
Chondroitin–4 sulfate
CH2OH
OSO3
COO
O
O
O
NHCOCH3
OH
O
N-acetylgalactosamine
CH2OSO3
?
O
O
COO
O
O
OH
NHCOCH3
O
OH
Glucuronic acid
N-acetylgalactosamine
Keratin sulfate
CH2OSO3
O
O
Intervertebral
disc
Capsular
ligament
Intertransverse
ligament
Posterior
Anterior
Figure 2-9â•… Lateral view of a cervical motion segment identifying the
ligamentous structures.
Chondroitin–6 sulfate
CH2OH
Anterior
longitudinal
ligament
Interspinous
ligament
OH
Glucuronic acid
OH
Posterior
longitudinal
ligament
O
OH
O
NHCOCH3
O
OH
Figure 2-8â•… Structure of chondroitin and keratin compounds.
of the intervertebral discs and the discs located within the pubic
symphysis and other joints of the extremities (e.g., knee). The
role of fibrocartilage is to support and stabilize the joints as well
as dissipate compressive forces. Fibrocartilage largely depends on
diffusion of nutrients contained in the adjacent trabecular bone.
Therefore, it depends on a “load-unload” mechanism to help the
diffusion of nutrients and removal of metabolic wastes.
Ligamentous Elements
The primary ligamentous structure of a synovial joint is the joint
capsule. Throughout the vertebral column the joint capsules are
thin and loose. The capsules are attached to the opposed superior
and inferior articular facets of adjacent vertebrae. Joint capsules in
the spine have three layers.10 The outer layer is composed of dense
fibroelastic connective tissue made up of parallel bundles of collagen fibers. The middle layer is composed of loose connective tissue
and areolar tissue containing vascular structures. The inner layer
consists of the synovial membrane. The fibers are generally oriented in a direction perpendicular to the plane of the facet joints.
This joint capsule covers the posterior and lateral aspects of the
zygapophyseal joint. The capsular ligaments provide flexion stability in the cervical spine.1 The ligamentum flavum covers the
joint capsules anteriorly and medially and connects the borders
of adjacent laminae from the second cervical vertebra to the first
sacral vertebra. These ligaments, referred to as yellow ligaments,
are composed of a large amount of elastic fibers. This allows for a
significant amount of tension to the ligament without permanent
deformation. Clinically this is an important characteristic for the
spine if it suddenly goes from full flexion to full extension. The
high elasticity of the ligamentum flavum minimizes the chances
of any impingement of the spinal cord. The anterior longitudinal ligament (ALL) is a fibrous tissue structure that is attached to
the anterior surfaces of the vertebral bodies, including part of the
sacrum. The ALL attaches firmly to the edges of the vertical bodies but is not firmly attached to the annular fibers of the disc. It is
narrowed at the level of the disc. The posterior longitudinal ligament (PLL) runs over the posterior surfaces of all of the vertical
bodies down to the coccyx. It has an interwoven connection with
the intervertebral disc and is wider at the disc level but narrower
at the vertebral body level. Both the ALL and PLL deform with
separation and approximation between the two adjacent vertebrae
and with disc bulging. The ALL has been found to be twice as
strong as the PLL.1 The intertransverse ligaments attach between
the transverse processes. They are fairly substantial in the thoracic
spine, but quite small in the lumbar spine. The interspinous and
supraspinatus ligaments attach between the spinous processes
(Figure 2-9).
Synovial Fluid
Synovial fluid is an ultrafiltrate of blood with additives produced
by the synovium to provide nourishment for the avascular articular
cartilage and contribute to the lubrication and protection of the
articular cartilage surfaces.11 The identity of the significant active
ingredient within synovial fluid that provides the near frictionless
performance of diarthrodial joints, has been the quest of researchers for many years. Initially, hyaluronic acid was thought to be the
lubricant, but it has not demonstrated the load-bearing properties
required within the physiologic joint. Currently lubricin is being
investigated as the possible substance within the synovial fluid with
the necessary attributes. Lubricin is the glycoprotein fraction of
synovial fluid that is secreted by surface chondrocytes and synovial
18
| Chiropractic Technique
cells. It has been shown to have the same lubricating ability because
of the surface-active phospholipids present in lubricin.12,13
Although the exact role of synovial fluid is still unknown, it is
thought to serve as a joint lubricant or at least to interact with the
articular cartilage to decrease friction between joint surfaces. This
is of clinical relevance because immobilized joints have been shown
to undergo degeneration of the articular cartilage.14 Synovial fluid
is similar in composition to plasma, with the addition of mucin
(hyaluronic acid), which gives it a high molecular weight and its
characteristic viscosity. Three models of joint lubrication exist. The
controversy lies in the fact that no one model of joint lubrication
applies to all joints under all circumstances.
According to the hydrodynamic model, synovial fluid fills in
spaces left by the incongruent joint surfaces. During joint movement, synovial fluid is attracted to the area of contact between
the joint surfaces, resulting in the maintenance of a fluid film
between moving surfaces. This model was the first to be described
and works well with quick movement, but it would not provide
adequate lubrication for slow movements and movement under
increased loads.
The elastohydrodynamic model is a modification of the hydrodynamic model that considers the viscoelastic properties of articular cartilage whereby deformation of joint surfaces occurs with
loading, creating increased contact between surfaces. This would
effectively reduce the compression stress to the lubrication fluid.
Although this model allows for loading forces, it does not explain
lubrication at the initiation of movement or the period of relative
zero velocity during reciprocating movements.15
In the boundary lubrication model, the lubricant is adsorbed
on the joint surface, which would reduce the roughness of the
surface by filling the irregularities and effectively coating the joint
surface. This model allows for initial movement and zero velocity movements. Moreover, boundary lubrication combined with
the elastohydrodynamic model, creating a mixed model, meets the
demands of the human synovial joint (Figure 2-10).
Boundary
Elastohydrodynamic
Hydrodynamic
Figure 2-10â•… Lubrication models for synovial joints. (Modified from
Hertling D, Kessler RM: Management of common musculoskeletal dis­
orders: Physical therapy principles and methods, ed 2, Philadelphia, 1990,
JB Lippincott.)
Articular Neurology
Articular neurology provides information on the nature of joint
pain, the relationship of joint pain to joint dysfunction, and the
role of manipulative procedures in affecting joint pain. The spinal
viscoelastic structures, including disk, capsule, and ligaments, were
found to have abundant afferents capable of monitoring proprioceptive and kinesthetic information.16 Therefore, spinal structures
are well suited to monitor sensory information and provide kinesthetic perception for coordinated motor control and movement.
Synovial joints are innervated by three or four varieties of
neuroreceptors, each with a wide variety of parent neurons.
The parent neurons differ in diameter and conduction velocity, representing a continuum from the largest heavily myelinated A α-fibers to the smallest unmyelinated C fibers. All are
derived from the dorsal and ventral rami, as well as the recurrent
meningeal nerve of each segmental spinal nerve (Figure 2-11).
Information from these receptors spreads among many segmental levels because of multilevel ascending and descending primary afferents. The receptors are divided into the four groups
according to their neurohistologic properties, which include
three corpuscular mechanoreceptors and one nociceptor.17
Type I receptors are confined to the outer layers of the joint
capsule and are stimulated by active or passive joint motions. Their
firing rate is inhibited with joint end approximation, and they
have a low threshold, making them very sensitive to movement.
Some are considered static receptors because they fire continually,
even with no joint movement. Because they are slow-adapting, the
effects of movement are long lasting. Stimulation of type I receptors is involved with the following:
1. Reflex modulation of posture, as well as movement (kinesthetic sensations), through constant monitoring of outer
joint tension
2. Perception of posture and movement
3. Inhibition of centripetal flow from pain receptors via an
enkephalin synaptic interneuron transmitter
4. Tonic effects on lower motor neuron pools involved in the
neck, limbs, jaw, and eye muscles
Type II mechanoreceptors are found within the deeper layers of
the joint capsule. They are also low-threshold and again are stimulated with even minor changes in tension within the inner joint.
Unlike type I receptors, however, type II receptors adapt very rapidly and quickly cease firing when the joint stops moving. Type II
receptors are completely inactive in immobilized joints. Functions
of the type II receptors are likely to include the following:
1. Movement monitoring for reflex actions and perhaps perceptual sensations
2. Inhibition of centripetal flow from pain receptors via an
enkephalin synaptic interneuron neutral transmitter
3. Phasic effects on lower motor neuron pools involved in the
neck, limbs, jaw, and eye muscles
Type III mechanoreceptors are found in the intrinsic and extrinsic ligaments of the peripheral joints, but they had been previously thought to be absent from all of the synovial spinal joints.
However, McLain18 examined 21 cervical facet capsules from three
normal human subjects and found type III receptors, although
they were less abundant than either type I or type II. These recep-
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
19
Spinal nerve root
Spinal nerve
ganglion
Sinuvertebral nerve
to annulus fibrosus
Nerves to spinous process
and interspinous ligament
Anterior primary
ramus
Nerve to articular capsule
Sinuvertebral nerve
to posterior
longitudinal
ligament
Nerves to yellow
ligament
Posterior primary rami
Articular facet
innervation
Posterior longitudinal
ligament
Sinovertebral nerve
to vertebral body
Nerve to joint
capsule
A
Interspinous and
supraspinous
ligaments
Nerve to vertebral body
Anterior longitudinal
ligament and nerve
B
Figure 2-11â•… Innervation of the outer fibers of the disc and facet joint capsule by the sinuvertebral nerve. A, Oblique posterior view. B, Top view.
(Modified from White AA, Panjabi MM: Clinical biomechanics of the spine, Philadelphia, 1978, JB Lippincott.)
tors are very slow adapters with a very high threshold because they
are innervated by large myelinated fibers. They seem to be the
joint version of the Golgi tendon organ in that they impose an
inhibitory effect on motor neurons. Although the functions of
type III receptors are not completely understood, it is likely that
they achieve the following:
1. Monitor direction of movement
2. Create a reflex effect on segmental muscle tone, providing a
“braking mechanism” against movement that over-displaces
the joint
3. Recognize potentially harmful movements
Type IV receptors are composed of a network of free nerve endings, as well as unmyelinated fibers. They are associated with
pain perception and include many different varieties with large
ranges of sensations, including itch and tickle. They possess an
intimate physical relationship to the mechanoreceptors and are
present throughout the fibrous portions of the joint capsule and
ligaments. They are absent from articular cartilage and synovial
linings, although they have been found in synovial folds.19,20 They
are very high-threshold receptors and are completely inactive in
the physiologic joint. Joint capsule pressure, narrowing of the
intervertebral disc, fracture of a vertebral body, dislocation of the
zygapophyseal joints, chemical irritation, and interstitial edema
associated with acute or chronic inflammation may all activate the
nociceptive system. The basic functions of the nociceptors include
the following:
1. Evocation of pain
2. Tonic effects on neck, limb, jaw, and eye muscles
3. Central reflex connections for pain inhibition
4. Central reflex connections for myriad autonomic effects
Postural control represents a complex interplay between the sensory
and motor systems and involves perceiving environmental stimuli,
responding to alterations in the body’s orientation within the environment, and maintaining the body’s center of gravity within the
base of support.21,22 Sensory information about the status of the
body within the environment emanates primarily from the proprioceptive, cutaneous, visual, and vestibular systems. Researchers23-25
have concluded that individuals rely primarily on proprioceptive
and cutaneous input to maintain normal quiet stance and to safely
accomplish the majority of activities of daily living, but must integrate information from multiple sensory systems as task complexity
and challenge to postural stability increase.
A relationship exists between mechanoreceptors and nociceptors such that when the mechanoreceptors function correctly, an
inhibition of nociceptor activity occurs.17 The converse also holds
true; when the mechanoreceptors fail to function correctly, inhibition of nociceptors will occur less, and pain will be perceived.17
Discharges from the articular mechanoreceptors are polysynaptic and produce coordinated facilitatory and inhibitory reflex
changes in the spinal musculature. This provides a significant
contribution to the reflex control of these muscles.17 Gillette19
suggests that a chiropractic adjustment produces sufficient force
to coactivate a wide variety of mechanically sensitive receptor
types in the paraspinal tissues. The A-δ-mechanoreceptors and
C-polymodal nociceptors, which can generate impulses during
and after �stimulation, may well be the most physiologically interesting component of the afferent bombardment initiated by highvelocity, low-amplitude manipulations. For normal function of
the joint structures, an integration of proprioception, kinesthetic
perception, and reflex regulation is absolutely essential.
20
| Chiropractic Technique
Pain-sensitive fibers also exist within the annulus fibrosus of
the disc. Malinsky20 demonstrated the presence of a variety of free
and complex nerve endings in the outer one third of the annulus. The disc is innervated posteriorly by the recurrent meningeal
nerve (sinuvertebral nerve) and laterally by branches of the gray
rami communicantes. During evaluation of disc material surgically removed before spinal fusion, Bogduk26 found abundant
nerve endings with various morphologies. The varieties of nerve
endings included free terminals, complex sprays, and convoluted
tangles. Furthermore, many of these endings contained substance
P, a putative transmitter substance involved in nociception.
Shinohara27 reported the presence of such nerve fibers accompanying granulation tissue as deep as the nucleus in degenerated
discs. Freemont and associates28 examined discs from individuals
free of back pain and from those with back pain. They identified
nerve fibers in the outer one third of the annulus in pain-free disc
samples, but they found nerve fibers extending into the inner one
third of the annulus and into the nucleus pulposus of the discs
from the pain sample. They suggest that their findings of isolated
nerve fibers that express substance P deep within diseased intervertebral discs may impart an important role in the pathogenesis
of chronic low back pain. Abundant evidence shows that the disc
can be painful, supporting the ascribed nociceptive function of the
free nerve endings.20,26-36
Because structure and function are interdependent, the study
of€joint characteristics should not isolate structure from function.
The structural attributes of a joint are defined as the anatomic
joint, consisting of the articular surfaces with the surrounding
joint �capsule and ligaments, as well as any intraarticular structures. The functional attributes are defined as the physiologic joint,
consisting of the anatomic joint plus the surrounding soft tissues,
including the muscles, connective tissue, nerves, and blood vessels
(Figure 2-12).
Rectus
femoris
tendon
Nerve
Gastrocnemius
muscle
Articular
cartilage
Joint capsule
and ligaments
Anatomic joint
Physiologic joint
Blood vessel
Menisci
Synovium
Bone
Periosteum
Figure 2-12â•… Structures that make up the anatomic joint and the
physiologic joint.
JOINT FUNCTION
The physiologic movement possible at each joint occurs when muscles contract or when gravity acts on bone to move it. This motion
is termed osteokinematic movement. Osteokinematic movement
describes how each bony joint partner moves relative to the others. Movement at a joint can be considered from two perspectives:
the proximal segment can rotate against the relatively fixed distal
segment or the distal segment can rotate against the relatively fixed
proximal segment. For example, knee flexion can occur with the
foot fixed on the ground during a deep-knee bend or while sitting
with the foot off the ground. A series of articulated segmental links, such as the connected shoulder girdle, arm, forearm,
wrist, and hand of the upper extremity, is considered a kinematic chain. A kinematic chain can be either open or closed.
An opened �kinematic chain describes a situation in which the
distal segment, such as the hand in the upper extremity, is not
fixed to an �immovable object and is free to move. A closed kinematic chain describes a situation in which the distal segment
is fixed to an immovable object, leaving the proximal segment
free to move.
The specific movements that occur at the articulating
joint surfaces are referred to as arthrokinematic movement.
Consideration of the motion between bones alone or osteokinematic movement is insufficient, because no concern is given
to what occurs at the joint and because movement commonly
involves coupling of motion around different axes. Furthermore,
arthrokinematic movements consider the forces applied to the
joint and include the accessory motion present in a particular
articulation.
It is therefore important to relate osteokinematic movement
to arthrokinematic movement when evaluating joint motion
(Figure 2-13). This involves determining the movement of the
mechanical axis of the moving bone relative to the stationary
joint surface. The mechanical axis of a joint is defined as a line
that passes through the moving bone to which it is perpendicular while contacting the center of the stationary joint surface
(Figure 2-14).
When one joint surface moves relative to the other, spin,
roll, slide, or combinations occur. MacConnail and Basmajian37
use the term spin to describe rotational movement around the
mechanical axis, which is possible as a pure movement only in
the hip, shoulder, and proximal radius. Roll occurs when points
on the surface of one bone contact points at the same interval of
the other bone. Slide occurs when only one point on the moving joint surface contacts various points on the opposing joint
surface (Figure 2-15).
In most joints of the human body, these motions occur simultaneously. The concave-convex rule relates to this expected coupling of rotational (roll) and translational (slide) movements.
When a concave surface moves on a convex surface, roll and slide
movements should occur in the same direction. When a convex
surface moves on a concave surface, however, roll and slide should
occur in opposite directions (Figure 2-16). Pure roll movement
tends to result in joint dislocation, whereas pure slide movement
causes joint surface impingement. Moreover, coupling of roll and
slide is important anatomically because less articular cartilage is
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
21
Spin
A
Mechanical
axis
Path followed by
mechanical axis
B
Figure 2-13â•… A, Osteokinematic movement of knee and trunk flexion. B, Arthrokinematic movements of tibiofemoral and T6–T7 joint
flexion.
necessary in a joint to allow for movement and may decrease wear
on the joint (Figure 2-17).
These concepts are instrumental in clinical decision-making regarding the restoration of restricted joint motion. Roll
and spin can be restored with passive range-of-motion procedures that induce the arthrokinematic movements of the dysfunctional joint. Manipulative (thrust) techniques are needed to
restore slide movements and can also be used for roll and spin
problems.38
In addition, when an object moves, the axis around which
the movement occurs can vary in placement from one instant to
another. The term instantaneous axis of rotation (IAR) is used to
denote this location point. Asymmetric forces applied to the joint
can cause a shift in the normal IAR. Furthermore, vertebral movement may be more easily analyzed as the IAR becomes more completely understood (Figure 2-18). White and Panjabi1 point out
that the value of this concept is that any kind of plane motion
can be described relative to the IAR. Complex motions are simply regarded as many very small movements with many changing
IARs.1 This concept is designed to describe plane movement, or
movement in two dimensions.
When three-dimensional motion occurs between objects,
a unique axis in space is defined called the helical axis of motion
(HAM), or screw axis of motion (Figure 2-19). HAM is the most
precise way to describe motion occurring between irregularly
shaped objects, such as anatomic structures, because it is difficult
to consistently and accurately identify reference points for such
objects.
Swing
Figure 2-14â•… Mechanical axis of a joint and MacConnail and
Basmajian’s concept of spin and swing.
Slide
b
b
a
a
Roll
b a
b
b
a
a
Figure 2-15â•… Arthrokinematic movements of roll and slide. (Modified
from Hertling D, Kessler RM: Management of common musculoskeletal
disorders: Physical therapy principles and methods, ed 2, Philadelphia, 1990,
JB Lippincott.)
22
| Chiropractic Technique
Position 1
Roll
Position 2
B1
Slide
B2
A1
A2
A
Roll
Instantaneous
axis of rotation
Slide
B
Figure 2-16â•… Concave-convex rule. A, Movement of concave surface on
Figure 2-18â•… Instantaneous axis of rotation. (Modified from White
AA, Panjabi MM: Clinical biomechanics of the spine, Philadelphia, 1978,
JB Lippincott.)
a convex surface. B, Movement of a convex surface on a concave surface.
Y
Pure slide
Pure roll
Impingement
Dislocation
Z
Figure 2-17â•… Consequences of pure roll or pure slide movements.
(Modified from Hertling D, Kessler RM: Management of common
musculoskeletal disorders: Physical therapy principles and methods, ed 2,
Philadelphia, 1990, JB Lippincott.)
Clearly, most movements occur around and through several
axes simultaneously, so pure movements in the human frame rarely
occur. The nature and extent of individual joint motion are determined by the joint structure and, specifically, by the shape and
direction of the joint surfaces. No two opposing joint surfaces are
perfectly matched, nor are they perfectly geometric. All joint surfaces have some degree of curvature that is not constant but changing from point to point. Because of the incongruence between joint
X
Figure 2-19â•… Helical axis of motion. (Modified from White AA,
Panjabi MM: Clinical biomechanics of the spine, Philadelphia, 1978, JB
Lippincott.)
surfaces, some joint space and “play” must be present to allow free
movement. This joint play is an accessory movement of the joint
that is essential for normal functioning of the joint.
For most synovial joints there is only one position, typically
at or near the end range of motion, in which the joint surfaces
fit together with the most congruency. The position of maximal
joint congruency is referred to as the joint’s close-packed position.
In this position most ligaments are taut and there is maximal
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
contact between the articular surfaces, making the joint very stable and difficult to move or separate. Any other position of the
joint is referred to as the loose-packed position. The joint surfaces
are generally less congruent and the ligaments and capsule are
relatively slackened. For most synovial joints, the loose-packed
position is toward flexion. The resting (maximal loose-packed)
position of a joint, or its neutral position, occurs when the joint
capsule is most relaxed and the greatest amount of play is possible. When injured, a joint often seeks this maximum loosepacked position to allow for swelling.
Joint surfaces will approximate or separate as the joint goes
through a range of motion. This is the motion of compression
and distraction. A joint moving toward its close-packed position
is undergoing compression, and a joint moving toward its loosepacked position is undergoing distraction37 (Table 2-3).
Joint motion consists of five qualities of movement that must
be present for normal joint function. These five qualities are joint
play, active range of motion, passive range of motion, end feel
or play, and paraphysiologic movement. From the neutral closepacked position, joint play should be present. This is followed by
a range of active movement under the control of the musculature. The passive range of motion is produced by the examiner
and includes the active range, plus a small degree of movement
into the elastic range. The elastic barrier of resistance is then
encountered, which exhibits the characteristic movement of end
feel. The small amount of movement available past the elastic
barrier typically occurs postcavitation and has been classified as
paraphysiologic movement. Movement of the joint beyond the
TABLE 2-3
paraphysiologic barrier takes the joint beyond its limit of anatomic integrity and into a pathologic zone of movement. Should
a joint enter the pathologic zone, there will be damage to the joint
structures, including the osseous and soft tissue components (see
Figures 3-22 and 3-23).
Both joint play and end-feel movements are thought to be necessary for the normal functioning of the joint. A loss of either
movement can result in a restriction of motion, pain, and most
likely, both. Active movements can be influenced by exercise and
mobilization, and passive movements can be influenced by traction and some forms of mobilization, but end-feel movements are
affected when the joint is taken through the elastic barrier, creating
a sudden yielding of the joint and a characteristic cracking noise
(cavitation). This action can be accomplished with deep mobilization and a high-velocity, low-amplitude manipulative thrust.
MECHANICAL FORCES ACTING ON
CONNECTIVE TISSUE
Whereas an understanding of structure is needed to form a foundation, an understanding of the dynamics of the various forces affecting
joints aids in the explanation of joint injury and repair. Functionally,
the most important properties of bone are its strength and stiffness,
which become significant qualities when loads are applied (Figure
2-20). Living tissue is subjected to many different combinations of
loading force throughout the requirements of daily living. Although
each type of loading force is described individually, most activities
produce varying amounts and combinations of all of them.
Close-Packed Positions for Each Joint
Region
Specific Joint
Close-Packed Position
Fingers
Knee
Distal interphalangeal joints
Proximal interphalangeal joints
Metacarpophalangeal joints
Intermetacarpal joints
Intercarpal joints
Radioulnar joints
Ulnohumeral joint
Radiohumeral joint
Glenohumeral joint
Acromioclavicular joint
Sternoclavicular joint
Distal interphalangeal joints
Proximal interphalangeal joints
Metatarsophalangeal joints
Intermetatarsal joints
Tarsometatarsal joints
Tibiotalar joint
Tibiofemoral joint
Hip
Coxofemoral joint
Spine
Three-joint complex
Maximal extension
Maximal extension
Maximal flexion
Maximal opposition
Maximal dorsiflexion
5 degrees of supination
Extension in supination
Flexion in supination
Abduction and external rotation
90 degrees of abduction
Maximal elevation
Maximal extension
Maximal extension
Maximal extension
Maximal opposition
Maximal inversion
Maximal dorsiflexion
Maximal extension and external
rotation
Maximal extension, internal
rotation, and abduction
Maximal extension
Hand
Wrist
Forearm
Elbow
Shoulder
Toes
Foot
Ankle
23
24
| Chiropractic Technique
Unloaded
Tension
Shear
Torsion
Compression
Bending
Combined loading
Figure 2-20â•… Loads to which bone may be subjectied. (Modified from
Soderberg GL: Kinesiology: Application to pathological motion, Baltimore,
1986, Williams & Wilkins.)
Tension Forces
The force known as tension occurs when a structure is stretched longitudinally. Tensile loading is a stretching action that creates equal
and opposite loads outward from the surface and tensile stress and
strain inward. Therefore, a tension force tends to pull a structure
apart, causing the cross-sectional area of the structure to decrease.
When a material is stretched in the direction of the pull, it contracts
in the other two directions. If the primary stress is tensile, there will
be secondary stresses that are compressive and vice versa.
The tension elements of the body are the soft tissues (fascia, muscles, ligaments, and connective tissue) and have largely
been ignored as construction members of the body frame. The
tension elements are an integral part of the construction and not
just a secondary support. In the spine, the ligaments are loaded in
tension.39 Tensile forces also occur in the intervertebral disc during
the rotational movements of flexion, extension, axial rotation, and
lateral flexion. The nucleus tends to bear the compressive load,
and the annular fibers tend to bear the tensile loads.
Compression Forces
Compression occurs when a load produces forces that push the
material together, creating a deforming stress. The behavior of a
structure in compression depends a great deal on its length and
how far or long the load is applied.
Compressive forces are transmitted to the vertebral body and
intervertebral disc in the spine. The nucleus pulposus is a semiliquid or gel that has the characteristics of a fluid or hydraulic
structure. It is incompressible and must therefore distort under
compressive loads. The nucleus pulposus dissipates the compressive force by redirecting it radially.
It is important clinically to note that mechanical failure occurs
first in the cartilaginous endplate when compressive forces applied
alone are too great. The result is nuclear herniation into the vertebral body, called a Schmorl’s node. However, failure may be
modified when the spine is loaded in either flexion or extension.
Compressive loads applied in flexion tend to cause anterior collapse of the endplate or vertebral body, where the bony structure is
weaker. With compressive loads applied in extension, a significant
percentage of the compressive load is transmitted through the facets, leading to capsular injuries.
Compressive loads applied with torque around the long axis can
produce circumferential tears in the disc annulus. Compression
loading (axial loading) on bone creates equal and opposite loads
toward the surface and compressive stress and strain inward, causing the structure to become shorter and wider. Compression fractures of the vertebral bodies are examples of failure to withstand
compressive forces.
Bending loads are a combination of tensile and compressive
loads. The magnitude depends on the distance of the forces from
the neutral axis. Fractures to long bones frequently occur through
this mechanism.
Shear Forces
The biomechanical effects on living things would be a great
deal easier to understand if the loads, stresses, and strains were
all either tensile or compressive ones. However, living things are
also subjected to shear forces. A shear force creates sliding or, more
specifically, resistance to sliding. Shear loading causes the structure
to deform internally in an angular manner as a result of loads
applied parallel to the surface of the structure.
Primarily, the facet joints and the fibers of the annulus fibrosus
resist shear forces in the spinal motion segment. Under normal
physiologic conditions, the facets can resist shear forces when they
are in contact. If, however, the disc space is narrowed by degeneration with subsequent thinning of the disc, abnormally high
stresses may be placed on the facet joints, and the limit of resistance to such forces is not well documented.40,41
Because there is no significant provision for resisting shear
stress, the risk of disc failure is greater with tensile loading
than with compression loading.1 However, the studies available
�demonstrating the effects of shear forces have been performed
mostly on cadavers in which the posterior elements have been
removed. The lumbar facets are aligned mostly in the sagittal
plane with an interlocking mechanism that only allows a few
degrees of rotation. Therefore, at least in the lower lumbar segments, the facet joints do provide resistance to shear stress.
Cancellous bone is most prone to fracture from shear loading, with the femoral condyles and tibial plateaus often falling
victim.
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
Torque Forces
Torsion occurs when an object twists, and the force that causes the
twisting is referred to as torque. Torque is a load produced by parallel forces in opposite directions about the long axis of a structure.
In a curved structure, such as the spine, bending also occurs when
a torque load is applied.
Farfan and co-workers42 estimate that approximately 90% of the
resistance to torque of a motion segment is provided by its disc. They
further state that the annulus provides the majority of the torsional
resistance in the lumbar spine and speculate that with torsional
injury, annular layers will tear, leading to disc degeneration.42 This
concept is developed around the idea that when torsional forces are
created in the spine, the annular fibers oriented in one direction will
stretch, whereas those oriented in the other direction will relax. The
result is that only half of the fibers are available to resist the force.
However, Adams and Hutton43 disagreed with Farfan and coworkers and demonstrated that primarily the facets resist the torsion of the lumbar spine and that the compressed facet was the
first structure to yield at the limit of torsion. Others have performed experiments that further suggest and support that the
posterior elements of the spine, including the facet joints and ligaments, play a significant role in resisting torsion.44,45 In deference
to Farfan and co-worker’s conclusions, these authors suggest that
torsion alone is unimportant as a causal factor of disc degeneration and prolapse, because rotation is produced by voluntary muscle activity and the intervertebral disc experiences relatively small
Axis
A
C
B
Tear
fracture
Fracture
D
Axis
25
stresses and strains. Bogduk and Twomey46 state that axial rotation
can strain the annulus in torsion, but ordinarily the zygapophyseal
joints protect it. Normal rotation in the lumbar spine produces
impaction of the facet joints, preventing more than 3% strain to
the annulus. With further rotation force, the impacted facet joint
can serve as a new axis of rotation, allowing some additional lateral
shear exerted on the annulus. Excessive rotational force can result
in failure of any of the elements that resist rotation.46 Fracture
can occur in the impacted facet joint; the pars interarticularis can
also fracture; capsular tears can occur in the nonimpacted facet
joint; and circumferential tears can occur in the annulus (Figure
2-21). Spiral fractures are another example of the results of torsional loads applied to long bones.
Newton’s Laws of Motion
The outcome of movement is determined by the forces applied to
the body being moved. Sir Isaac Newton, based on the teachings
of Galileo, observed that forces were related to mass and motion
in a predictable fashion. His “laws of motion” form the framework
for describing the relationship between forces applied to the body
and the consequences of those forces on human motion. Newton’s
laws of motion are the law of inertia, the law of acceleration, and
the law of action-reaction.
Law of Inertia
The first law of motion states that a body remains at rest or in
constant velocity except when compelled by an external force to
change its state. Therefore, a force of some kind is required to
start, stop, or alter linear motion. Inertia is related to the amount
of energy required to alter the velocity of the body or overcome its
resistance. Each body has a point about which its mass is evenly
distributed. This point, called the center of mass, can be considered
where the acceleration of gravity acts on the body. For the entire
upright human body, the center of mass lies just anterior to the
second sacral vertebra.
Law of Acceleration
The second law of motion states that the acceleration of the body
is directly proportional to the force causing it, takes place in the
same direction in which the force acts, and is inversely proportional to the mass of the body. It is from this law that the equation force (F) is equal to mass (m) times acceleration (a) is derived.
Newton’s second law can also be used to provide a work-energy
relationship. Work is equal to the product of the force applied to
an object and the distance the object moves. Furthermore, power
can then be defined by work divided by time.
Annular
tear
Figure 2-21â•… Effects of rotation on lumbar segments. A, Rotation is limited by impaction of facet joint. B, Further rotation causes a shift in the axis
of rotation. C, The impacted facet is exposed to fracture, and the distracted
facet is exposed to avulsion or capsular tear. D, The disc is exposed to lateral shear that can lead to circumferential tears in the annulus. (Modified
from Bogduk N, Twomey LT: Clinical anatomy of the lumbar spine, ed 2,
Melbourne, Australia 1991, Churchill Livingstone.)
Law of Action-Reaction
The third law of motion states that for every action there is an
equal and opposite reaction. This means that in every interaction,
there is a pair of forces acting on the two interacting objects. The
size of the forces on the first object equals the size of the force on
the second object. The direction of the force on the first object is
opposite to the direction of the force on the second object. Forces
always come in pairs—equal and opposite action-reaction force
pairs. When the two equal and opposite forces act on the same
26
| Chiropractic Technique
object, they cancel each other so that no acceleration (or even no
motion) occurs. This is not an example of the third law, but of
equilibrium between forces. Newton’s third law is one of the fundamental symmetry principles of the universe.
PROPERTIES OF CONNECTIVE TISSUE
The response of connective tissue to various stress loads contributes significantly to the soft tissue component of joint dysfunction.
Within the past several decades, a great deal of scientific investigation has been directed to defining the physical properties of
connective tissue. The composition, proportion, and arrangement
of biologic materials that compose the connective tissues associated with joints strongly influence the mechanical performance
of the joints. The biologic materials are fibers, ground substance,
and cells blended in various proportions based on the mechanical
demands of the joint.47
Connective tissue contributes to kinetic joint stability and
integrity by resisting rotatory moments of force. When these
rotatory moments of force are large, considerable connective tissue power is required to produce the needed joint stability and
integrity. Connective tissue is made up of various densities and
spatial arrangements of collagen fibers embedded in a protein�polysaccharide matrix, which is commonly called ground substance.
Collagen is a fibrous protein that has a very high tensile strength.
Collagenous tissue is organized into many different higher-order
structures, including tendons, ligaments, joint capsules, aponeuroses, and fascial sheaths. The principal sources of passive resistance at the normal extremes of joint motion include ligaments,
tendons, and muscles. Therefore, under normal and pathologic
conditions, the range of motion in most body joints is predominantly limited by one or more connective tissue structures. The
relative contribution of each to the total resistance varies with the
specific area of the body.
All connective tissue has a combination of two qualities—Â�
elastic stretch and plastic (viscous) stretch (Figure 2-22). The term
stretch refers to elongation in a linear direction and increase in
length. Stretching, then, is the process of elongation. Elastic stretch
represents springlike behavior, with the elongation produced
by tensile loading being recovered after the load is removed. It
is therefore also described as temporary, or recoverable, elongation. Plastic (viscous) stretch refers to putty-like behavior; the linear deformation produced by tensile stress remains even after the
stress is removed. This is described as nonrecoverable, or perma­
nent, elongation.
The term viscoelastic is used to describe tissue that represents
both viscous and elastic properties. Most biologic tissues, including tendons and ligaments, are viscoelastic materials. Viscoelastic
Tensile
force
Elastic qualities
Viscous qualities
Figure 2-22â•… Model of connective tissue properties.
materials possess time-dependent or rate-sensitive stress-strain
relationships.48 The viscous properties permit time-dependent
plastic or permanent deformation. Elastic properties, on the other
hand, result in elastic or recoverable deformation. This allows it to
rebound to the previous size, shape, and length.
Different factors influence whether the plastic or elastic component of connective tissue is predominantly affected. These include
the amount of applied force and the duration of the applied force.
Therefore, the major factors affecting connective tissue deformation are force and time. With a force great enough to overcome
joint resistance and applied over a short period, elastic deformation occurs. However when the same force is applied over a long
period, plastic deformation occurs.
When connective tissue is stretched, the relative proportion of
elastic and plastic deformation can vary widely, depending on how
and under what conditions the stretching is performed. When tensile forces are continuously applied to connective �tissue, the time
required to stretch the tissue a specific amount �varies inversely with
the force used. Therefore, a low-force �stretching method requires
more time to produce the same amount of �elongation as a higherforce method. However, the proportion of tissue �lengthening
that remains after the tensile stress is removed is€ greater for the
low-force, long-duration method. Of course, high force and long
duration also cause stretch and possibly rupture of the connective
tissue.
When connective tissue structures are permanently elongated, some degree of mechanical weakening occurs, even though
outright rupture has not occurred. The amount of weakening
depends on the way the tissue is stretched, as well as how much it
is stretched. For the same amount of tissue elongation, however, a
high-force stretching method produces more structural weakening
than a slower, lower-force method.
Because plastic deformation involves permanent changes in
connective tissue, it is important to know when plastic deformity
is most likely to occur. The greatest effect occurs when positions
of stress are maintained for long periods. Awkward sleep postures
and stationary standing for extended periods can create plastic
changes that have the potential for skeletal misalignment, joint
dysfunction, and instability.
After trauma or surgery, the connective tissue involved in
the body’s reparative process frequently impedes function; it
may abnormally limit the joint’s range of motion as a result of
fibrotic tissue replacing elastic tissue. Scar tissue, adhesions, and
fibrotic contractures are common types of pathologic connective
tissue that must be dealt with during chiropractic manipulative
procedures.
Connective tissue elements can lose their extensibility when
their related joints are immobilized.49 With immobilization,
water is released from the proteoglycan molecule, allowing connective tissue fibers to contact one another and encouraging
abnormal cross-linking that results in a loss of extensibility.50
It is hypothesized that manual therapy can break the crosslinking and any intraarticular capsular fiber fatty adhesions,
thereby providing free motion and allowing water inhibition
to occur. Furthermore, procedures can stretch segmental muscles, stimulating spindle reflexes that may decrease the state of
hypertonicity.51
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
27
The response of connective tissue to various stress loads contributes significantly to the soft tissue component of joint dysfunction. Within the past several decades, a great deal of scientific
investigation has been directed to defining the physical properties
of connective tissue.
Muscle
The role of muscles is to move bone and allow the human body to
perform work. In the normal man, muscle accounts for approximately 40% to 50% of body weight. For the woman, this falls to
approximately 30% of total body weight. Three types of muscle
are in the body: striated skeletal muscle, nonstriated smooth involuntary muscle, and cardiac muscle. Only the skeletal muscle is
under voluntary control.
There are three gross morphologic muscle types in striated
muscle (Figure 2-23). Parallel muscles have fibers that run parallel throughout the length of the muscle and end in a tendon. This
type of muscle is essentially designed to rapidly contract, although
it typically cannot generate a great deal of power. Pennate muscles are those in which the fibers converge onto a central tendon.
A muscle of this type is unipennate if the fibers attach to only one
side of a central tendon, and it is bipennate if the muscle attaches
to both sides of a central tendon. Finally, there is a multipennate
muscle in which the muscle fibers insert on the tendon from a
variety of differing directions. This form of muscle can generate
large amounts of power, although it performs work more slowly
than a parallel muscle.
Muscle comprises three layers (Figure 2-24). An epimysium
formed of connective tissue surrounds the muscle; a perimysium
separates the muscle cells into various bundles; and an endomysium surrounds the individual muscle cells. The muscle fibers also
have three layers. The outermost layer is formed of collagen fibers.
A basement membrane layer comprises polysaccharides and
A
B
C
Figure 2-23â•… Morphologic muscle types. A, Unipennate. B, Bipennate.
C, Multipennate.
Endomysium
Epimysium
Perimysium
Figure 2-24â•… Connective Tissue Layers.
protein and is approximately 500 Å thick. The innermost layer,
the sarcolemma, forms the excitable membrane of a muscle.
Muscle fibers contain columns of filaments of contractile proteins. In striated muscle, these molecules are interrelated layers
of actin and myosin molecules. These myofibrils are suspended
in a matrix called sarcoplasm, composed of the usual intracellular components. The fluid of the sarcoplasm is rich with potassium, magnesium, phosphate, and protein enzymes. Numerous
mitochondria lie close to the actin filaments of the I bands, suggesting that the actin filaments play a major role in using adenosine triphosphate formed by the mitochondria.52 The sarcoplasmic
reticulum functions in a calcium ion equilibrium. A transverse
tubular system transmits membrane depolarization from the
muscle cell to the protein. Also located within the sarcoplasm is
the protein myoglobin that is necessary for oxygen binding and
oxygen transfer.
Skeletal muscle occurs in two forms, originally known as white
and red muscle. The white muscle is a fast-twitch, or phasic, muscle.
It has a rapid contraction time and contains a large amount of glycolytic enzyme. Essentially, this muscle allows for rapid function
necessary for quick contractions for short periods. Red muscle is a
slow-twitch, or tonic, muscle. It contracts much more slowly than
does white muscle and contains a great deal more myoglobin and
oxidative enzymes. Red muscle is more important in static activities that require sustained effort over longer periods. Standing is a
good example of this. In the human body, each individual muscle
is composed of a mix of both types of muscle.
When a stimulus is delivered to a muscle from a motor nerve,
all fibers in the muscle contract at once.53 Two types of muscle
contractions have been defined. During an isotonic contraction, a
muscle shortens its fibers under a constant load. This allows work
to occur. During an isometric contraction, the length of the muscle
does not change. This produces tension, but no work. No muscle
can perform a purely isotonic contraction, because each isotonic
contraction must be initiated by an isometric contraction.
Muscle contraction refers to the development of tension within
the muscle, not necessarily creating a shortening of the muscle.
When a muscle develops enough tension to overcome a resistance so that the muscle visibly shortens and moves the body
28
| Chiropractic Technique
part, concentric contraction is said to occur. Acceleration is thus
the ability of a muscle to exert a force (concentric contraction)
on the bony lever to produce movement around the fulcrum to
the extent intended.
When a given resistance overcomes the muscle tension so that
the muscle actually lengthens, the movement is termed an eccentric
contraction. Deceleration is the property of a muscle being able to
relax (eccentric contraction) at a controlled rate. There are numerous clinical applications of the eccentric contraction of muscles,
particularly in posture.
Muscles can perform various functions because of their ability
to contract and relax. One property is that of shock absorption,
another is acceleration, and a third is deceleration. Each is very
important to the overall understanding of the biomechanics of the
body and is discussed separately. The predominant responsibility
for the dissipation of axial compression shocks rests with the musculotendon system. As a result, shock causes many musculoskeletal
complaints. Shin splints, plantar fasciitis, Achilles tendinitis, lateral
epicondylitis, as well as some forms of back pain, can result from
the body’s inability to absorb and dissipate shock adequately.
Although the muscular system is the primary stabilizer of the
joint, if the muscle breaks down, the ligaments take up the stress.
This is often seen in an ankle sprain, when the muscles cannot
respond quickly enough to protect the joint and the ligaments
become sprained or torn. If the ligaments are stretched but not
torn completely through, this can lead to a chronic instability of the
joint, especially if the surrounding musculature is not adequately
rehabilitated. When the muscles fail and the ligaments do not maintain adequate joint stability, the stress cannot be fully absorbed by
those tissues, and the bone and its architecture take up the stress.
Forces applied to joints in any position may cause damage to
the bony structure, ligaments, and muscles. Tensile forces generated by muscle contractions can pull apart the cement from the
osteons, resulting in fractures (the most common of which is at the
base of the fifth metatarsal from the pull of the peroneus brevis).
Calcaneal fractures from the pull of the Achilles tendon also occur
through this mechanism. Because the closed-packed position has
the joint surfaces approximated and capsular structures tight, an
improperly applied force may cause fracture of the bone, dislocation of the joint, or tearing of the ligaments. Kaltenborn54 states
that it is important to know the closed-packed position for each
joint because testing of joint movements and manipulative procedures should not be done to the joint in its closed-packed position
(see Table 2-3). When an improperly applied force is applied in
the open-packed position, the joint laxity and loss of stability may
allow damage to the ligaments and supporting musculature.
One of the signs of segmental dysfunction is the presence of
muscle hypertonicity. Localized increased paraspinal muscle tone
can be detected with palpation, and in some cases with electromyography. Janda55 recognizes five different types of increased
muscle tone: limbic dysfunction, segmental spasm, reflex spasm,
trigger points, and muscle tightness. Liebenson56 has discussed the
treatment of these five types using active muscle contraction and
relaxation procedures.
Acute traumatic injury to muscle is generally considered to
result from a large force of short duration, influencing primarily the elastic deformation of the connective tissue. If the force is
beyond the elastic range of the connective tissue, it enters the plastic range. If the force is beyond the plastic range, tissue rupture
occurs. More commonly encountered by the chiropractor is the
microtrauma seen in postural distortions, repetitive minor trauma
occurring in occupational and daily living activities, and joint
dysfunction as a result of low gravitational forces occurring over a
long period, thus creating plastic deformation.
Immobilization is often associated with a decrease in muscle elasticity. This condition is called muscle contracture, but the
mechanism is not yet clear. Muscle immobilized in a shortened
position develops less force and tears at a shorter length than freely
mobile muscle with a normal resting length.57 For this reason, vigorous muscle stretching has been recommended for muscle tightness.55 However, for the stretch to be effective, the underlying
joints should be freely mobile. Patients therefore often require
manipulation that specifically moves associated joints before muscle stretching. Selective atrophy of fast-twitch type 2 fibers has also
been identified in pain-related immobilization of a joint,58 further
supporting the importance of proper joint function.
Ligaments
Ligaments are usually cordlike or bandlike structures made of
dense collagenous connective tissue similar to that of a tendon.
Ligaments are composed of type I and type III collagen, with
intervening rows of fibrocytes. Also interwoven with the collagen
bundles are elastin fibers that provide extensibility. The amount
of elastin varies from ligament to ligament. Ligaments exhibit a
mechanical property called crimping that provides a shock-absorbing mechanism and contributes to the flexibility of the ligament.
Spinal ligaments serve two roles, allowing smooth motion
within the spine’s normal range of motion and protecting the spinal cord by limiting excessive motion and absorbing loads.59 Jiang60
identified that stretching of spinal ligaments results in “a barrage of sensory feedback from several spinal cord levels on both
sides of the spinal cord.” This sensory information has been found
to ascend to many higher (cortical) centers. Such findings provide provocative evidence that the spinal ligaments, along with the
Z joint capsules and the small muscles of the spine (interspinales, intertransversarii, and transversospinalis muscles), play an important role in
mechanisms related to spinal proprioception (joint position sense) and
may play a role in the neural activity related to spinal adjusting.61
Large loads are capable of overcoming the tensile resistance of ligaments, resulting in complete- or partial-tear injuries. Ligament healing occurs through the basic mechanisms of inflammation, repair,
and remodeling. Immobilization of ligamentous tissue results in a
diminished number of small-diameter fibers62 that presumably lead
to joint stiffness. However, the precise mechanism by which immobilization leads to joint stiffness has not been determined. It likely
results from a combination of intraarticular adhesion formation and
active contraction of ligaments by fibroblasts.63–65 Using a cat model,
deformation or stress in the supraspinous ligament, and possibly in
other spinal ligaments, recruits multifidus muscle force to stiffen one
to three lumbar motion segments and prevent instability.66 Strong
muscular activity is seen when loads that can cause permanent damage to the ligament are applied, indicating that spastic muscle activity
and possibly pain can be caused by ligament overloading.
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
Facet Joints
The common factor in all of the spinal segments from the atlantooccipital joint to the pelvis is the fact that each has two posterior
spinal articulations. These paired components have been referred
to as the zygapophyseal (meaning an “oval offshoot”) joints and are
enveloped in a somewhat baggy capsule, which has some degree
of elasticity. Each of the facet facings is lined with articular cartilage, as is the case with all contact-bearing joint surfaces, with the
exception of the temporomandibular joint and the sternoclavicular joint. These joints have intracapsular fibrocartilaginous discs
that separate the joint surfaces.
Compared with intervertebral discs, facet joints have been the
focus of very little biomechanical research. Yet these structures
must control patterns of motion, protect discs from shear forces,
and provide support for the spinal column. The orientation of the
joint surface varies with each spinal region, largely governing the
degree of freedom each region can accomplish (Figure 2-25).
0º
45º
A
120º
60º
B
90º
90º
C
Figure 2-25â•… Facet planes in each spinal region viewed from the side
and above. A, Cervical (C3–C7). B, Thoracic. C, Lumbar. (Modified
from White AA, Panjabi MM: Clinical biomechanics of the spine, ed2,
Philadelphia, JB Lippincott, 1990.)
29
Because these joints are true diarthrodial (synovial) articulations, each has a synovial membrane that supplies the joint surfaces with synovial fluid. The exact role of synovial fluid is still
unknown, although it is thought to serve as a joint lubricant or,
at least, to interact with the articular cartilage to decrease friction
between joint surfaces. In addition, the synovium may be a source
of nutrition for the avascular articular cartilage. Intermittent compression and distraction of the joint surfaces must occur for an
adequate exchange of nutrients and waste products to occur.2
Furthermore, as mentioned, immobilized joints have been shown
to undergo degeneration of the articular cartilage.14 Certainly,
the nature of synovial joint function and lubrication is of interest
because there is evidence that the facet joints sustain considerable
stress and undergo degenerative changes.
The capsule is richly innervated with nociceptors (pain) and
mechanoreceptors (proprioception), allowing the supporting structures to react to many combinations of tension and compression
movements imposed by different postures and physical activity.
Each movement of the joint must first overcome the surface tension of the capsule, but must then be able to return to its original
position maintaining joint apposition. The lateral portions of the
capsule are much more lax and contain fewer elastic fibers.67 Creep
during sustained lumbar flexion occurs significantly faster than
creep during repetitive lumbar flexion, suggesting that both result
in immediate and residual laxity of the joint and stretch of the facet
joint capsule, which could increase the potential for joint pain.68
Although the posterior joints were not designed to bear much
weight, they can share up to about one third of this function with
the intervertebral disc. Moreover, as a part of the three-joint complex, if the disc undergoes degeneration and loses height, more
weight-bearing function will fall on the facets. During long periods
of axial loading, the disc loses height through fluid loss, thereby
creating more weight-bearing on the facets on a daily basis.
The posterior joints also have been found to contain fibroadipose meniscoids that apparently function to adapt to the incongruity of the articular surfaces, but the clinical significance of which
remains controversial. Bogduk and Engel69 provide an excellent
review of the meniscoids of the lumbar zygapophyseal joints.
Although the genesis of their article was as a literature review to
support the contention that the meniscoids could be the cause of
an acute locking of the low back because of entrapment, the article
also provided a comprehensive review of the anatomic consideration of lumbar meniscoids.
The meniscoids appear to be synovial folds continuous with
the periarticular tissues and with both intracapsular and extracap�
sular components. Microscopically, the tissue consisted of loose
connective and adipose tissue, mixed with many blood vessels
(Figure 2-26). The meniscoids could present in various shapes,
including annular menisci found in the thoracic region, with linguiform menisci and filiform menisci commonly found in the
lumbar region.70
These meniscoid structures can project into the joint space
when the joint surfaces of articular cartilage are not in contact.
Bogduk and Engel69 noted two groups; one is located along the
dorsal and ventral margins of the joint and one is located at the
superior and inferior aspects of the joint. In their view, only the
ones located along the dorsal and ventral borders of the joint
30
| Chiropractic Technique
Articular
cartilage
Fibrous cap
of meniscoid
Inferior
articular
facet
Superior
articular
facet
Articular
capsule
Adipose tissue
cells of the base
of the meniscoid
Figure 2-26â•… Fibroadipose meniscoid in a lumbar facet joint.
(Modified from Bogduk N, Engel R: The menisci of the lumbar zygapophyseal joints: A review of their anatomy and clinical significance, Spine
9:454, 1984.)
represent true meniscoids. Functionally, Bogduk and Engel believe
these structures may help to provide greater stability to a lumbar
zygapophyseal joint by helping to distribute the load over a wider
area. In their words, meniscoids play a “space-filling” role.69
Clinically and theoretically these meniscoids may become
entrapped or extrapped.71 Entrapment of the meniscoid between
the joint surfaces itself is not believed to be painful, although pain
can be created by traction on the joint capsule through the base
of the meniscoid. This could, through a cascade of events, lead
to more pain and reflex muscle spasm, known as acute locked low
back, which is amenable to manipulative therapy. Extrapment of
the meniscoid may occur when the joint is in a flexed position
and the meniscoid is drawn out of the joint but fails to reenter the
joint space on attempted extension. It gets stuck against the edge
of the bony lip or articular cartilage, causing a buckling of the
capsule that serves as a space-occupying lesion. Pain is produced
through capsular distention.72
Giles and Taylor67,73 examined the innervation of meniscoids
(synovial folds) in the lumbar zygapophyseal joints, using both
light microscopy and transmission electron microscopy. The
authors removed part of the posteromedial joint capsule along
with the adjacent ligamentum flavum and synovial folds after a
laminectomy, fixed these specimens in various solutions, and prepared them for microscopy. They demonstrated that neurologic
structures were located in the areas studied. Nerves seen in the
synovial fold were 0.6 to 12 µm in diameter. These neurologic
structures may give rise to pain.
Taylor and Twomey74 suggest that because of their rich blood
supply, spinal joint meniscoids do not undergo degeneration with
age as do the intervertebral disc and articular cartilage. However,
with degenerative changes to disc and especially articular cartilage,
the meniscoid inclusions are exposed to abnormal biomechanical
forces that may result in their demise.
Adams and Hutton75 examined the mechanical function of
the lumbar apophyseal joints on spines taken from cadavers. The
authors wanted to examine various loading regimens on the function of these joints. They found that the lumbar zygapophyseal
joints can resist most of the intervertebral shear force only when
the spine is in a lordotic posture. These joints also can aid in resisting the intervertebral compressive force and can prevent excessive movement from damaging the intervertebral discs. The facet
surfaces protect the posterior annulus, whereas the capsular ligament helps to resist the motion of flexion. The authors noted that
in full flexion the capsular ligaments provide nearly 40% of the
joint’s resistance. They conclude that “the function of the lumbar
apophyseal joints is to allow limited movement between vertebrae
and to protect the discs from shear forces, excessive flexion and
axial rotation.”75
Taylor and Twomey74 studied how age affected the structure
and function of the zygapophyseal joints. They took transverse
sections of the lumbar spine from cadavers ranging in age from
fetus to 84 years and prepared them in staining media. They noted
that fetal and infant lumbar zygapophyseal joints are coronally
oriented, which only later (in early childhood) become curved
or biplanar joints. In the adult, the joint has a coronal component in the anterior third of the joint and a sagittal component
in the posterior two thirds of the joint. The joint is generally
hemicylindrical.
The structures located in the anterior third of the joint, primarily articular cartilage and subchondral bone, tend to show
changes that are related to loading the joint in flexion. The posterior part of the joint shows a variety of different changes related to
age. There may be changes from shearing forces. The subchondral
bone thickens as it ages and is wedge-shaped. These changes occur
because of loading stresses from flexion.74
Taylor and Twomey74 are careful to note that they could make
no clinical correlation with their findings, which is one of the
problems with cadaveric studies of this sort. They believe that this
work has biomechanical implications; they believe that the lumbar zygapophyseal joints limit the forward translational component of flexion to only a very small displacement. Indeed, they
believe this fact may be the most important component limiting
forward flexion. Although the lumbar facet joints are oriented in
the sagittal plane, they are not purely sagittal, and flexion with
anterior translation will result in impaction of the facets limiting
this movement.57
Intervertebral Discs
The intervertebral discs are fibrocartilaginous mucopolysaccharide structures that lie between adjoining vertebral bodies. In the
adult there are 23 discs, each given a numeric name based on the
segment above. Thus the L5 disc lies between the fifth lumbar segment and the sacrum, and the L4 disc lies between the fourth and
fifth lumbar segments. In the early years of life, the discs between
the sacral segments are replaced with osseous tissue, but remain as
rudimentary structures; they are generally regarded as having no
clinical significance.
The unique and resilient structure of the disc allows for its function in weight-bearing and motion. The anterior junction of two
vertebrae is an amphiarthrodial symphysis articulation formed by
the two vertebral endplates and the intervertebral disc. The discs
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
are responsible for approximately one fourth of the entire height
of the vertebral column. The greater the height of the intervertebral disc as compared to the height of the vertebral body, the
greater the disc to vertebral body ratio and the greater the spinal
segmental mobility. The ratio is greatest in the cervical spine (2:5)
and least in the thoracic spine (1:5), with the lumbar region (1:3)
in between. A disc has three distinct components: the annulus
fibrosus, the nucleus pulposus, and the cartilaginous endplates.
The cartilaginous endplates are composed of hyaline cartilage
that separates but also helps attach the disc to the vertebral bodies. There is no closure of cortical bone between the hyaline cartilage and the vascular cancellous bone of the vertebral body. The
functions of the endplates are to anchor the disc, to form a growth
zone for the immature vertebral body, and to provide a permeable
barrier between the disc and body. This role allows the avascular
disc material to receive nutrients and repair products.
The annulus fibrosus is a fibrocartilage ring that encloses and
retains the nucleus pulposus, although the transition is gradual,
with no clear distinction between the innermost layers of the
annulus and outer aspect of the nucleus. The fibrous tissue of the
annulus is arranged in concentric, laminated bands, which appear
to cross one another obliquely, each forming an angle of about
30 degrees to the vertebral body (Figure 2-27). The annular fibers
of the inner layers are attached to the cartilaginous endplates, and
the outer layers are attached directly to the osseous tissue of the
vertebral body by means of Sharpey fibers.76
Superficially, the ALL and the PLL reinforce the fibers. The
PLL is clinically significant in that as it courses caudally, its width
narrows until it covers only approximately 50% of the central portion of the lower lumbar discs. The weakest area of the annulus,
and hence the area most likely to be injured, is the posterolateral
aspect. This is the most likely spot for a disc herniation in the
lumbar spine.77
The annulus fibrosus contains little elastic tissue, and the
amount of stretch is limited to only 1.04 times its original length,
with further stretch resulting in a tearing of fibers. The functions
of the annulus fibrosus include enclosing and retaining the nucleus
pulposus, absorbing compressive shocks, forming a structural unit
between vertebral bodies, and allowing and restricting motion.
The nucleus pulposus is the central portion of the disc and
is the embryologic derivative of the notochord. It accounts for
approximately 40% of the disc and is a semifluid gel that deforms
easily, but is considered incompressible. The nucleus is composed
of a loose network of fine fibrous strands that lie in a mucoprotein matrix containing mucopolysaccharides, chondroitin sulfate,
hyaluronic acid, and keratin sulfate. These large molecules are
strongly hydrophilic, capable of binding nearly nine times their
volume of water, and are therefore responsible for the high water
content of the disc. In young adults, the water content of a disc
approaches 90% and maintains an internal pressure of approximately 30 pounds per square inch.1 The water content, however,
steadily decreases with age. The composition of the nucleus produces a resilient spacer that allows motion between segments, and
although it does not truly function as a shock absorber, it does
serve as a means to distribute compressive forces.
The image of the nucleus as a round ball between two hard
surfaces must be abandoned. This gives the impression that the
nucleus can roll around between the two endplates. The only
means for significant nuclear migration is through a tear in the
annular fibers, allowing the nucleus to change shape but not actually shift position. The result of nuclear migration is a potential
change in the instantaneous axis of movement and potential aberrant segmental motion.
The intervertebral disc is a vital component for the optimal, efficient functioning of the spinal column. In conjunction
with the vertebral bodies, the discs form the anterior portion of
the functional unit responsible for bearing weight and dissipating shock. In so doing, it distributes loads, acts as a flexible buffer between the rigid vertebrae, permits adequate motion at low
loads, and provides stability at higher loads.
The simple compression test of the disc has been one of the most
popular experiments because of the importance of the disc as a major
load-carrying element of the spine. Axial compression forces continually affect the disc during upright posture. The nucleus bears 75%
of this force initially, but redistributes some to the annulus.
Furthermore, the ability of the disc to imbibe water causes it
to “swell” within its inextensible casing. Thus the pressure in the
nucleus is never zero in a healthy disc. This is termed a preloaded
30
A
Nucleus
Annular
laminates
31
30
B
Figure 2-27â•… Intervertebral disc. A, Nucleus pulposus and annulus fibrosus. B, Orientation of annular fibers. (Modified from White AA, Panjabi
MM: Clinical biomechanics of the spine, Philadelphia, 1978, JB Lippincott.)
32
A
| Chiropractic Technique
B
C
D
Figure 2-28â•… Effects of axial loads on vertebral body and disc. A,
Normal disc height. B, Normal disc under mild to moderate axial load,
showing slight approximation of bodies. C, Diseased disc under same
axial load, showing significant loss of disc height. D, Endplate fracture
from significant axial load causing a Schmorl node.
state. The preloaded state gives the disc a greater resistance to
forces of compression.
With age and exposure to biomechanical stresses, the chemical nature of the disc changes and becomes more fibrous. This
reduces the imbibition effect and, in turn, the preloaded state. As
a result, flexibility is diminished and more pressure is exerted on
the annulus and peripheral areas of the endplate. A disc that has
been injured deforms more than a healthy one.
The preloaded state also explains the elastic properties of
the disc. When the disc is subjected to a force, the disc exhibits
dampened oscillations over time. If the force is too great, however,
the intensity of the oscillations can destroy the annulus, thus
accounting for the deterioration of intervertebral discs that have
been exposed to repeated stresses.
Compressive forces are transmitted from endplate to endplate
by both the annulus and the nucleus. When compressed, the disc
bulges in the horizontal plane. A diseased disc compresses more,
and, as this occurs, stress is distributed differently to other parts of
the functional unit, notably the apophyseal articulations. Because
the disc is prepared for axial compression, it should be noted
that under large loads, the endplate will fracture (Schmorl node)
(Figure 2-28) or the anterior vertebral body will collapse.
Axial tensile stresses are also produced in the annulus during the
movements of flexion, extension, and lateral flexion. The motions
create compression stresses ipsilaterally and tensile stresses contral-
aterally. This causes a bulging (buckling) on the concave side and a
contraction on the convex side of the disc (Figure 2-29).
Axial rotation of the spine also produces tensile stresses in the
disc. Studies have shown that the greatest tensile capabilities of
the disc are in the anterior and posterior regions; the center portion of the disc is the weakest. When the disc is subjected to torsion, shear stresses are produced in the horizontal and axial planes.
Shear stresses act in the horizontal plane, perpendicular to the
long axis of the spine. It has been found that torsional forces, and
hence shear forces, can be the injury-causing load factors. During
normal movements, the disc is protected from excessive torsion
and shear forces by the lumbar facet joints.
All viscoelastic structures, which include the disc, exhibit hysteresis and creep. Cadaveric studies allowed Twomey and Taylor78
to study creep and hysteresis in the lumbar spine. Hysteresis refers
to the loss of energy when the disc or other viscoelastic structures
are subjected to repetitive cycles of loading and unloading. It is the
absorption or dissipation of energy by a distorted structure. For
example, when a person jumps up and down, the shock energy
is absorbed by the discs on its way from the feet to the head. The
larger the load, the greater the hysteresis.1 When the load is applied
a second time, the hysteresis decreases, meaning there is less capacity to absorb the shock energy (load). This implies that the discs
are less protected against repetitive loads.
Creep is the progressive deformation of a structure under constant load. When a load is applied to a viscoelastic structure, it
immediately deforms under the load. If the load is maintained,
there will be continued deformation over time. As might be
expected, the creep and hysteresis created in differing types of load
forces (e.g., flexion loading vs. extension loading) may differ, but
this has not been quantified for the lumbar spine.
Because the disc is under the influence of the preloaded state of
the nucleus, movements have specific effects on the behavior of the
nucleus and annular fibers. When a distraction force is applied, the
tension on the annular fibers increases and the internal pressure of
the nucleus decreases. When an axial compression force is applied
symmetrically, the internal pressure of the nucleus increases and
transmits this force to the annular fibers. The vertical force is transformed into a lateral force, applying pressure outward.
Tensile
stress
Tension
Compressive
stress
Compression
Instantaneous axis of rotation
Instantaneous axis of rotation
Figure 2-29â•… Disc stresses with bending movements of flexion, extension, and lateral flexion. Tension is produced on the convex side, whereas
�compression and buckling occur on the concave side.
Chapter 2â•… Joint Anatomy and Basic Biomechanics |
During the asymmetric movements of flexion, extension, and
lateral flexion, a compressive force is applied to the side of movement, and a tensile force occurs on the opposite side. The tension
transmitted from the nucleus to the annular fibers helps to restore
the functional unit to its original position by producing a “bowstring–like” tension on the annular fibers.
During axial rotation, some layers of the annulus are stretched
and others are compressed (slackened). Tension forces reach a
maximum within the internal layers of the annulus. This has a
strong compressive force on the nucleus and causes an increased
internal pressure proportional to the degree of rotation.
Kurowski and Kubo79 investigated how degeneration of the
intervertebral disc influences the loading conditions on the lumbar
spine. Because disc degeneration is common, it will almost inevitably contribute to low back dysfunction by influencing motion
and load bearing at each individual level. Kurowski and Kubo79
examined load transmission through the lumbar spine with differing amounts of disc degeneration and used fine element analysis to study stress transmission. In a healthy disc, they found the
highest effective stresses in the center of the endplate of the vertebra, but in an unhealthy and degenerated disc, they found these
stresses in the lateral aspects of the endplates, as well as in the
cortical wall and vertebral body rims.
MODELs OF SPINE FUNCTION
Understanding the overall function of the human spine has proved
to be difficult and frustrating. It is important to view the spine as
an integrated functioning unit. It must be remembered, however,
that the spine is also a part of the larger locomotor system. If consideration is not given to the whole locomotor system, the potential for clinical failure results.
The spine is a mechanical structure characterized by the vertebrae articulating with each other in a controlled manner through
a complex of levers (vertebrae), pivots (facets and discs), passive restraints (ligaments), and activations (muscles).1 There are
three important and fundamental biomechanical functions of
the spine.1 First and foremost, the spine must house and protect
the spinal cord, yet allow for transmission of neurologic impulses
to and from the periphery. Second, it must provide support for
the upright posture by being able to absorb shock and bear and
�transfer weight from the resultant bending moments of the head
and trunk to the pelvis. Finally, it must allow for sufficient physiologic motions between the body parts in the six degrees of freedom. The vertebral column is a flexible axis composed of the
articulated vertebrae. The spine must be rigid for it to maintain
upright bipedal posture, yet it has to deform its shape to allow
for mobility. In addition, it houses and protects the spinal cord
and provides a means for neurologic transmission to and from
the periphery.
Many models of spine function have been developed,80–84 each
attempting to define spine function according to new and different
parameters. However, each of these models fails in some way to
consider all of the characteristics and requirements of the spine’s
complex and integrated structural and functional relationship.
A spine model has been proposed that considers the struc-
33
tural integrity of the spine as a whole, providing an interesting
look at how adaptation to upright biped posture places specific
demands on the spinal components. A structure is defined as
any assemblage of materials that is intended to sustain loads.
Each life form needs to be contained by a structure. Even the
most primitive unicellular organism has to be enclosed and protected by cell membranes that are both flexible and strong, yet
capable of accommodating cell division during reproduction.
With advancement of and competition in evolving life forms,
the structure requirements need to become more sophisticated.
The majority of living tissues have to carry mechanical loads of
one kind or another. Muscles also have to apply loads, changing
shape as they do so. By making use of contractile muscles as tension members and strong bones as compression members, highly
developed vertebrate animals have been able to withstand necessary loads and still allow for mobility, growth, and evolution.
Parallels have been drawn between the spine and the mast of a
ship. Compressive loads are concentrated in the vertebrae of the
spine and the wooden mast of the ship. Tension loads are diffused into tendons, skin, and other soft tissues of the body and
into the ropes and sails of the ship to maintain an upright position. However, a ship mast is immobile, rigidly hinged, vertically
oriented, and dependent on gravity. These rigid columns require
a heavy base to support the incumbent load. In contrast, the
biologic structure of the spine must be a mobile, flexibly hinged,
low-energy-consuming, omnidirectional structure that can function
in a gravity-free environment.85
Comparisons have also been made between the spine and a
bridge (or truss). The musculoskeletal configuration of a large,
four-legged animal (e.g., a horse) is capable of bearing a substantial load in addition to it own weight, rests on four slender compression members (leg bones), and is supported efficiently by an
assortment of tension members (tendons, muscles, and skin).
Trusses have flexible, even frictionless, hinges, with no bending
moments about the joint. The support elements are either in tension or compression only. Loads applied at any point are distributed about the truss as tension or compression.85
Although this model sounds quite plausible for the spine, it is
not a complete explanation. Most trusses are constructed with tension members oriented in one direction. This means that they function in only one direction and can therefore not function as the
mobile, omnidirectional structure necessary for describing the spine
�functions. Moreover, bridges do not have to move, whereas vertebrate
animals do. Furthermore, the comparison cannot be directly applied
to the human skeleton, because the human skeleton is upright and
the forces are applied in the long axis rather than along it.
Levin85 identifies another class of truss called tensegrity struc­
tures that are omnidirectional so that the tension elements always
function in tension regardless of the direction of the applied force.
The structure that fits the requirements of an integrated tensegrity model has been described and constructed as the tensegrity
icosahedron. In this structure, the outer shell is under tension,
and the vertices are held apart by internal compression struts that
seem to float in the tension network (Figure 2-30). In architecture, stable form is generated through an equilibrium between
many interdependent structures, each of which is independently
in a state of disequilibrium. Complex architecture cannot be
34
| Chiropractic Technique
Compression
member
Tension
member
Figure 2-30â•… Tensegrity icosahedron with rigid compression members and elastic tension members. Multiple units sharing a compression
member form a structural model of the spine. (Modified from Bergmann
TF, Davis PT: Mechanically assisted manual techniques: Distraction proce­
dures, St Louis, 1998, Mosby.)
broken up into isolated pieces without losing qualities that are
inherent to the structural whole. This is extremely important in
biologic systems in which every functional unit is literally more
than the sum of its constituent parts.86
Many architectural structures depend on compressive forces
for structural integrity. Compression-dependent structures are
inherently rigid and poorly adapted for a rapidly changing environment. Most naturally occurring structures depend on natural
forces for their integrity.87 The human body can be described as a
tensile structure in which tensional integrity (tensegrity) is maintained by muscles suspended across compression-resistant bones.
Fuller88 spoke for many years of a universal system of structural
organization of the highest efficiency based on a continuum of
tensegrity. Fuller’s theory of tensegrity developed out of the discovery of the geodesic dome, the most efficient of architectural forms,
and through study of the distribution of stress forces over its structural elements. A tensegrity system is defined as an architectural
construction that is composed of an array of �compression-resistant
struts (bones) that do not physically touch one another but are
interconnected by a continuous series of tension elements (muscles and ligaments).86 Because action and reaction are equal and
opposite, the tension forces have to be compensated by equal and
opposite compressive forces and vice versa.
Gravitational force is a constant and greatly underestimated
stressor to the somatic system. The most obvious effect of gravitational stress can be evaluated by careful observation of posture,
which is both static and dynamic. The static alignment of body
mass with respect to gravity is constantly adjusted by dynamic neuromuscular coordination as the individual changes position. Over
time, individual static postural alignment conforms to inherent
connective tissue structure, as well as the cumulative functional
demands of both static and dynamic postural conditions.
Musculoligamentous function is also significantly influenced
by, as well as responsible for, static and dynamic postural alignment.89 The development of asymmetric functional barriers in the
spine likely has more than one cause. A unifying factor, however, is
the transfer of forces within the soft tissues that creates altered and
asymmetric tension, namely the tensegrity mechanism.
When the various principles and research noted here are combined, a more complete picture of spinal biomechanics is developed in which pathologic changes may ultimately be better studied
as well.
c0015
Joint Assessment Principles
and€Procedures
Outline
THE MANIPULABLE LESION
SUBLUXATION
VERTEBRAL SUBLUXATION
COMPLEX
Mechanical Components
Joint Malposition
Joint Fixation (Hypomobility)
Clinical Joint Instability and
Hypermobility
Mechanical Models of Spinal
Dysfunction and
Degeneration
Neurobiologic Components
Theory of Intervertebral
Encroachment and Nerve
Root Compression
Theory of Altered Somatic and
Visceral Reflexes
Inflammatory and Vascular
Components
Vascular Congestion
Inflammatory Reactions
JOINT SUBLUXATION/
DYSFUNCTION SYNDROME
SPINAL LISTINGS
CLINICAL EVALUATION OF JOINT
SUBLUXATION/DYSFUNCTION
SYNDROME
T
36
36
37
38
38
39
41
42
43
43
45
46
46
46
47
47
47
Examination Procedures and
Diagnostic Criteria
History
Physical Examination
Pain and Tenderness
Asymmetry
Range-of-Motion
Abnormality
Tone, Texture, and Temperature
Abnormality
Special Tests
Clinical Usefulness of Joint
Assessment Procedures
Reliability
Validity
Responsiveness
Utility
Outcome Assessment
Procedures
Symptoms of Joint Subluxation/
Dysfunction Syndrome
Patient Observation
Gait Evaluation
Postural Evaluation
Leg Length Evaluation
Range-of-Motion
Assessment
Measurement Procedures
Palpation
he doctor of chiropractic views the human being as a
dynamic, integrated, and complex living thing who has an
innate capacity for self-healing.1-6 Chiropractic health care
focuses on the evaluation and treatment of neuromusculoskeletal (NMS)-based disorders, but does not disregard the multiple
potential causes of ill health and the complex nature of health
maintenance.7,8
In keeping with this philosophy and the responsibility as
“Â�portal-of-entry” health care providers, chiropractors must
maintain broad and thorough diagnostic skills. The Council
on Chiropractic Education (CCE) defines the primary care chiropractic physician as an “individual who serves as a point for
direct access to health care delivery; the doctor of chiropractic’s responsibilities include (1) patient’s history; (2) completion
and/or interpretation of physical examination and specialized
Â�diagnostic procedures; (3) assessment of the patient’s general
health status and resulting diagnosis; (4) provision of chiropractic care and/or consultation with continuity in the comanagement, or referral to other health care providers; and (5)
development of Â�sustained health care partnership with patients.”9
50
50
50
50
51
51
51
51
52
52
52
53
53
53
53
54
55
55
56
59
59
60
Chapter
3
Reliability of Palpation
Procedures
Validity of Palpation
Procedures
Sacroiliac Articulation
Bony Palpation
Soft Tissue Palpation
Motion Palpation
Accessory Joint Motion Joint Challenge
(Provocation)
Percussion
Muscle Testing
Provocative (Orthopedic) Tests
Radiographic Analysis
Spinal X-ray
Examinations
Functional X-ray
Examination
Videofluoroscopy
Clinical Use of X-ray
Examination
Instrumentation
Algometry
Thermography
Galvanic Skin Resistance
Surface Electromyography
CLINICAL DOCUMENTATION
61
63
65
65
66
67
69
71
72
73
74
74
76
77
78
79
79
79
80
80
81
82
Before �applying therapy, the chiropractor must first ascertain if
there is a clinical basis for treatment. The chiropractic physician
who chooses to limit therapeutic alternatives must still possess
the skills necessary to determine if patients seeking their care have
a health problem responsive to the specific treatments they provide.10 This dictates that chiropractors be trained to screen and
evaluate a broad range of complaints if they wish to maintain
their primary contact privileges. Diagnostic skills must have sufficient depth to screen all organ systems of the body for those conditions that are and are not amenable to chiropractic treatment.
The social expectation and regulatory requirement of a primary
contact provider are to provide a suitable health status assessment
and initial clinical impression regardless of the patient presentation or the health care professional’s particular discipline, philosophy, or theories.
A core area of focus and expertise for the chiropractic
�physician is the evaluation of the NMS system. This chapter
focuses on the �knowledge, principles, and evaluation procedures central to the process of determining whether a patient
is a candidate for adjustive therapy.
35
36
| Chiropractic Technique
THE MANIPULABLE LESION
Manual therapy has been proposed as an effective treatment for a
wide variety of conditions, but it is most commonly associated with
disorders that have their origins in pathomechanical or pathophysiologic alterations of the locomotor system and its synovial joints.
As a result, manual therapy is based on assessment procedures that
take into consideration both functional and structural alteration
of the NMS system. Haldeman11 has referred to this process as
the identification of a manipulable lesion. Spinal manipulation is
thought to act on this manipulable or functional joint lesion, but
given the historical presumption of this entity, it is somewhat surprising that there is not more information on its pathomechanical properties.12 The lesion is viewed as a set of possible individual
maladies responsible for the patient’s symptoms.13,14
The identification of the common functional and structural
components of the manipulable lesion is critical to the management of this condition, but it has also contributed to the misconception that all manipulable disorders have the same pathologic
basis. The overwhelming majority of disorders effectively treated
with chiropractic adjustments do display joint and somatic functional alterations, but many pathologic processes can induce joint
dysfunction.
A diagnosis of joint dysfunction syndrome identifies local
altered mechanics, but it does not identify the underlying nature
of the dysfunction. Although joint derangements may present as
independent clinical syndromes, they are more commonly associated with other identifiable disorders and injuries of the NMS
system.15-23
If chiropractors limit their examination to the identification of
structural or functional signs of joint dysfunction, they may minimize the extent of the disorder and the effectiveness of their treatment. For example, both the patient with acute disc herniation
and the patient with acute facet syndrome present with clinical
signs of joint dysfunction. An evaluation confined to the detection of joint dysfunction might not uncover the underlying pathomechanical and pathophysiologic differences between these two
conditions and the distinctions in therapy that might be necessary.
Furthermore, other disease states or traumatic events that would
contraindicate adjustive therapy may induce spinal malpositions
or fixations.
A singular diagnosis of joint dysfunction or subluxation syndrome
should be reserved for instances when it is determined to be the
sole identifiable lesion; the terms should not be used as a category
for all conditions treated with adjustive therapy. When joint dysfunction is perceived as the sole cause of the disorder being considered for treatment, adjustive therapy may be the only treatment
necessary. However, when joint dysfunction is secondary to other
disorders that are not responsive to adjustive treatments, other
effective treatments should be provided or made available to the
patient by referral.
Determination of the appropriateness of adjustive therapy
should not be based on the presence of a fixation, malposition,
or spinal listing alone. The cause of the altered mechanics indicates whether adjustive therapy or some other form of therapy is
in order.23
SUBLUXATION
Within the chiropractic profession, the manipulable lesion has
been equated primarily with the term joint subluxation. The concept of subluxation is a central defining clinical principle and the
source of contentious debate and disagreement within the profession.24 Mootz suggests that the chiropractic profession’s attention
to subluxation (pro and con) is found in virtually every dimension
of the profession’s existence, be it clinical, scientific, philosophical, or political.25 He identifies four distinct ways that subluxation
is used by the profession, each with merits and liabilities. They
are25:
• Subluxation as chiropractic theory: Subluxation is used as an
explanatory mechanism for physical effects of chiropractic
intervention.
• Subluxation as professional identity: Subluxation forms the
entire basis of and for chiropractic practice.
• Subluxation as a clinical finding: Subluxation serves as target for
localizing manipulative and adjustive intervention.
• Subluxation as a clinical diagnosis: Subluxation represents a
�distinct clinical condition or syndrome.
Historically, joint subluxation was defined predominantly in structural terms.1,2,23,26-30 The founder of chiropractic, D.D. Palmer,
defined joint subluxation as a “partial or incomplete separation,
one in which the articulating surfaces remain in partial contact.”31
Central to Palmer’s original subluxation hypothesis was the concept that vertebral subluxations could impinge on the spinal nerve
roots (NRs) as they exit through the intervertebral foramina. This
was postulated to obstruct the flow of vital nerve impulses from
the central nervous system to the periphery and to induce lowered
tissue resistance and potential disease in the segmentally innervated tissues.1,2,8,29,31-35 Palmer went so far as to suggest that the
primary cause of all disease could be related to subluxations and
interruption of normal “tone—nerves too tense or too slack.”1,8
The most impassioned supporter of this concept was D.D.
Palmer’s son, B.J. Palmer. Throughout his career, B.J. Palmer
ardently promoted a monocausal concept of disease,8,27,28,36,37
specifically stating that chiropractic is “a science with provable
knowledge of one cause of one disease being an internal interference of the internal flow of abstract mental impulses or nerve
force flow supply, from above down, inside out.”36
Although the profession today emphasizes the important relationship between health and the structure and function of the
NMS system,4-7,32-35,38,39 it does not promote a monocausal concept of subluxation-induced disease.7-10,37-40 The monocausal
concept runs contrary to much of the profession’s recent literature24,34,35,37-39 and to the view held by the overwhelming majority
of practicing chiropractors.8 Although a small minority of chiropractors still promotes this extreme view, both the profession’s
national associations and the CCE have disavowed it.9,39
Beginning with the published work of Gillet,41-46 Illi,47 and
Mennell,48,49 and later through the writings of Sandoz23,30,50,51 and
Faye,52,53 the importance of the dynamic characteristics of joint
subluxation moved to the forefront. As a result, joint integrity
was defined not only in structural terms but also in functional
terms.23,30,34,35,42-56 Within this context, joint subluxation took on a
Chapter 3╅ Joint Assessment Principles and€Procedures |
broader definition, and joint malposition became a possible sign
of disturbed joint function, not absolute confirmation.
This view provides a more dynamic perspective and suggests
that minor joint misalignment does not necessarily predict the
presence or absence of joint dysfunction or the direction of possible restricted movement.23,30,50-54 From this perspective, joints
do not have to be malpositioned to be dysfunctional. Joint fixation can occur with the joint fixed in a neutral position, or it can
have multiple planes of joint restriction.23,30,50,57,58 Consequently,
�treatment decisions concerning adjustive therapy and adjustive
vectors, once based predominantly on the direction of malposition, grew to incorporate an assessment of the functional status of
the patient including an assessment of joint mobility.41-55 Today,
consideration is given to both the static and dynamic components
of spinal dysfunction, including presence or absence of joint pain
with loading (joint provocation/challenge).23,32,34
Other health care providers within the field of manual medicine also struggle with multiple definitions and explanations
for manipulable lesions.59-63 Box 3-1 contains a list of terms and
definitions commonly used to describe functional or structural
disorders of the synovial joints. A common principle behind
all of these concepts is that there is a somatic component to
disease and that dysfunction of the NMS system can affect a
BOX 3-1
37
patient’s overall health status as well as the ability to recover
from injury and disease.
VERTEBRAL SUBLUXATION COMPLEX
Because of continued professional debate and increasing scientific
inquiry, a trend toward viewing subluxations as complex clinical
phenomena has unfolded.* Rather than a condition definable by
one or two characteristics, subluxation is more commonly presented as a complex, multifaceted pathologic entity, known as the
vertebral subluxation complex (VSC) (see Box 3-1). The VSC is a
conceptual model and should not be confused with the vertebral
subluxation syndrome. The vertebral subluxation/dysfunction syndrome defines a clinical disorder identified by its presenting symptoms and physical signs.
Gitelman, and later Faye, were the first to promote this broader
model and its theoretic components.51,56,65,66 More recently, Lantz67
and Gatterman60,64 have championed this cause. In 1994, a consensus60 presented broader definitions for the VSC that seems to
be growing in recognition and acceptance.
* References 23, 26, 30, 31-35, 39, 55, 56, 60, 64.
Terms Describing Functional or Structural Disorders of the Synovial Joints
ORTHOPEDIC SUBLUXATION
A partial or incomplete dislocation.59
SUBLUXATION
The alteration of the normal dynamic, anatomic, or physiologic
relationships of contiguous articular structures56; a motion segment in which alignment, movement integrity, or physiologic
function is altered, although the contact between the joint surfaces remains intact60; an aberrant relationship between two
adjacent articular structures that may have functional or pathologic sequelae, causing an alteration in the biomechanical or
neurophysiologic reflections of these articular structures or body
systems that may be directly or indirectly affected by them.10
SUBLUXATION SYNDROME
An aggregate of signs and symptoms that relate to pathophysiology or dysfunction of spinal and pelvic motion segments or to
peripheral joints.60
SUBLUXATION COMPLEX
A theoretic model of motion segment dysfunction (subluxation)
that incorporates the complex interaction of pathologic changes in
nerve, muscle, ligamentous, vascular, and connective tissues.10
JOINT DYSFUNCTION
Joint mechanics showing area disturbances of function without
structural change—subtle joint dysfunctions affecting quality
and range of joint motion. Definition embodies disturbances in
function that can be represented by decreased motion, increased
motion, or aberrant motion.61
Joint hypomobility: decreased angular or linear joint
movement
Joint hypermobility: increased angular or linear joint
�movement; aberrant joint movements are typically not present.
Clinical joint instability: increased linear and aberrant joint
movement; the instantaneous axes of rotation (centroids) and
patterns of movement are disturbed.
SOMATIC DYSFUNCTION
Impaired or altered function of related components of the
somatic (body framework) system; skeletal, arthrodial, and
myofascial structures; and related vascular, lymphatic, and neural elements.62
Osteopathic Lesion
A disturbance in musculoskeletal structure or function, as well
as accompanying disturbances of other biologic mechanisms.
A term used to describe local stress or trauma and subsequent
effects on other biologic systems (e.g., effects mediated through
reflex nerve pathways, including autonomic supply of segmentally related organs).63
Joint Fixation
The state whereby an articulation has become temporarily
immobilized in a position that it may normally occupy during any phase of physiologic movement; the immobilization of an articulation in a position of movement when the
joint is at rest or in a position of rest when the joint is in
movement.30
38
| Chiropractic Technique
Although the trend toward a broader perspective of subluxation has helped move the profession from a simplistic and reductionistic model of spinal health, it has not necessarily advanced
the investigation into its existence and nature. Reaching consensus on subluxation theory and expanding the number of clinical
spinal disorders that are supposedly subluxation-related does not
provide proof of their presence as the primary “lesion” treated
by chiropractors. Faye suggests that the subluxation complex
is a �conceptualization for organizing the essential information
�relevant to treatment, allowing a chiropractor to examine a person
in both a classic orthoneurologic manner and using a biomechanical approach to arrive at a double diagnosis.68 The first assesses the
state of the pathologic tissue changes and also aids in determining
the prognosis. The second determines the therapeutic procedures
to be used and the treatment schedule.68
Nelson24 states that subluxation theory lacks several necessary
properties that would allow it to serve as a vehicle for research.
First, a theory should attempt to explain existing phenomena and
observations; the VSC theory has not been used to explain any
specific clinical phenomena. Lantz67 adds that the VSC does not
identify any single event or process as the sole causative element in
the complex process of subluxation development. Second, a theory should make predictions; the VSC theory makes none. It does
not lead in any particular direction or draw any distinction or
specific conclusions. The VSC theory suggests that any number
of pathologic conditions affecting tissue are possible, with none
being more important than any other.67 Third, a theory should be
testable and falsifiable so that a study may provide results or observations that either confirm or refute the theory. The VSC theory
is so encompassing, allowing for a wide range of mitigating and
changing circumstances, that it is difficult to evaluate. Nelson24
points out that this circular type of argument and reasoning (tautology) validates itself simply by renaming accepted principles as a
new theory or principle. A tautology has the virtue of being irrefutable, but the deficiency of being useless. It explains nothing,
makes no predications, draws no distinctions, and is untestable.
There is value in reaching consensus on the theoretic pathophysiologic and pathomechanical components of functional disorders of
spinal motion segments, but mainly for purposes of dialogue and
research. The VSC therefore remains a theoretic model in need of
investigation. The VSC theory should not be considered as one grand
theory, but rather a series of interlocking and interdependent principles. The principles that form a basis for considering the existence
and significance of the subluxation should be consistent with current
basic science precepts. They must reflect current practice and educational standards, be clinically meaningful, and present a distinct and
unique point of view. Unfortunately, the available research data tell
us little about the presumed clinical meaningfulness of the traditional
chiropractic lesion. Clinical meaningfulness refers to the practical
value of a concept in directing the clinician to successful resolution of
the health problem the patient has presented. Unfortunately, no one
has systematically addressed the predictive power (if any) of subluxation correction for any specific disease or “condition.” None of the
controlled clinical trials of the effects of spinal manipulative therapy
has, to date, included a subluxation element.69,70
Keating and colleagues point out that the concept of chiropractic subluxation stands pretty much today as it did at the dawn of
the 20th �century: It is an interesting notion without validation.71
Although there is a strong intraprofessional commitment to the
subluxation construct and there are reimbursement strategies that
are legally based on subluxation, there is no scientific “gold standard” for detecting these clinical entities.72 The term chiropractic
subluxation continues to have as much or more political than scientific meaning.73
Subluxation is still the most common term chiropractors use
to describe the spinal joint disorders they treat.74 However, chiropractors are much more likely to view subluxations as disorders that have either structural or functional components rather
than simply malpositioned joints. Furthermore, the VSC has been
described using theoretic pathologic components broadly divided
into mechanical, inflammatory-vascular, and neurobiologic categories. Although these divisions are modeled after those proposed
by previous authors, they do not represent an established professional convention. Instead the categories and topics presented
here represent an overview of the theoretic effects of the VSC and
are not intended to be an all-inclusive or exhaustive treatise on the
subject. While these categories are discussed separately, it must
be emphasized that although these characteristics may occur in
isolation, they can also occur in varying combinations. Some are
emphasized more than others, depending on the mode of onset,
rate of repair, and length of treatment time.
Mechanical Components
The mechanical category of the VSC includes derangements or
disorders of the somatic structures of the body that lead to altered
joint structure and function. Derangement of the articular soft
tissues and mechanical joint dysfunction may result from acute
injury, repetitive-use injury, faulty posture or coordination, aging,
immobilization, static overstress, congenital or developmental
defects, or other primary disease states.*
Joint Malposition
Historically, the basis for subluxation was founded on the concept
that traumatic events could lead to altered joint position and that
this malposition would interfere with neurologic impulses. Both
the chiropractic profession (through D.D. Palmer) and the osteopathic profession (through A.T. Still) have stressed joint position
as an important quality for normal joint function.1,94
One of the oldest concepts from the literature on manipulation is the interdependence of structure and function. In other
words, structure determines function and function determines
structure. When there is a change in structure, there will be a
change in function. Therefore, if a structural alteration is identified, a functional change should also be perceived. When a spinal
joint is either acutely traumatized or undergoes chronic repetitive stresses, it is assumed that asymmetric muscle tension is likely
to develop and hold the joint in a position away from its neutral alignment. The central idea is that misaligned positions of
skeletal components can result in movement limitations, associated inflammatory changes, and irritation of nociceptors leading
*References 15-23, 26, 30, 34, 50-54, 56, 75-93.
Chapter 3╅ Joint Assessment Principles and€Procedures |
to pain. From a historical perspective, the chiropractic profession
primarily viewed spinal subluxations as a structural failure that
alters body function.95
The concept of static vertebral misalignment is difficult to support, however. Triano cites evidence that there is no “normal position” between vertebrae in the sense of the historic subluxation
argument.95 The spine and the component parts are not perfectly
symmetric in their development. Spinous processes in particular
are quite prone to asymmetric growth. It is also very unlikely that
one could palpate a displacement of a few millimeters or degrees
based on the location of the spinous processes. Identification of
joint malposition is typically through static palpation or radiographic mensuration. Both of these procedures have only fair to
poor inter- and intraobserver agreement. Furthermore, there is no
evidence that supports a change in alignment following manipulative intervention. Clearly the “bone-out-of-place” concept is not
likely to be the sole explanation for subluxation.25,96
Joint Fixation (Hypomobility)
A more biologically plausible model of spinal joint pain incorporates abnormal joint mechanics and postulates that vertebral hypomobility can cause pain and abnormal spinal mechanics because of
changes in sensory input from spinal and paraspinal tissues. Work
by Henderson and associates provide the first preliminary anatomic
evidence that altered spinal mechanics may produce neuroplastic
changes in the dorsal horn of the spinal cord.97-99 Their preliminary
data suggest that chronic vertebral hypomobility (fixation) at L4
through L6 in the rat affects synaptic density and morphology in
the superficial dorsal horn of the L2 spinal cord level.99
Soft Tissue Injury and Repair. A commonly proposed source
of joint fixation (hypomobility) and dysfunction is periarticular
soft tissue injury with its resultant fibrosis and loss of elasticity and
strength.15-22,54,56,57,75-77 Soft tissue injury and fibrosis may result from
acute or repetitive trauma to muscular, tendinous, myofascial, or ligamentous tissue. Regardless of the mechanism of injury, an ensuing
inflammatory response is triggered57 resulting in extracellular accumulation of exudates and blood. Platelets then release thrombinconverting fibrinogen into fibrin, which organizes into collagenous
scar tissue, resulting in a variety of soft tissue and articular adhesions.
This process is considered to be nonspecific and often excessive in
the case of traumatic NMS injuries.15,79 As a consequence, early conservative management is often directed at limiting the extent of the
inflammatory response. Therapies directed at minimizing the extent
of associated inflammatory exudates are helpful in reducing pain and
muscle spasm and in promoting early pain-free mobilization and
flexible repair.79,83-85,93,100-113 Aggressive early care and mobilization
provide the best opportunity for optimal healing and an early return
to work for the patient. Bed rest and prolonged inactivity increase
the chances of long-term disability and lost work time.103,105,114,115
The exudates that form as a byproduct of injury and inflammation set the stage for the next step in the process of connective
tissue repair. They provide the matrix for the development of
granulation tissue and scar formation. The formation of granulation tissue is predominantly carried out by the proliferation of
fibroblasts and the synthesis and deposit of collagen tissue. The
collagen is initially very poorly organized and must add additional collagen cross-linkages and reorganize along planes of stress
39
to improve the tensile strength of the injured area. This process
of repair and remodeling may take months and may result in less
than optimal restoration and extensibility of the involved tissue.
Immobilization slows the process of recovery, leading to loss of
strength and flexibility and potential intra-articular fatty adhesions.75,76,83-93 Immobilization also leads to dehydration, causing
proteoglycans to approximate and stick together.83,84,88 If injury
or immobilization leads to decreased flexibility, therapies such
as articular adjustments or joint mobilization should be directed
toward the restoration of motion.15,79,82,102
Myofascial Cycle. Painful conditions capable of triggering persistent muscle hypotoncity are additional sources of restricted joint
motion (Figure 3-1). Muscle contraction, once initiated, may become
MYOFASCIAL CYCLE
Joint dysfunction
Repetitive use
Chronic postural
stress
Exposure to cold
Visceral disease
Physical trauma
MUSCLE
STRAIN
Structural
inadequacies
Uncoordinated
movements
Emotional tension
Pain
Retained metabolites
Edema (inflammation)
Muscle splinting
Vasoconstriction
ischemia
Joint dysfunction
Myofascial syndromes
Sustained contraction
Fibrous reaction
Soft tissue contractures
Persistent joint and somatic dysfunction
Figure 3-1â•… Myofascial conditions are triggered by many causes and
can become self-perpetuating sources of pain, muscle spasm, and joint
dysfunction.
40
| Chiropractic Technique
a self-perpetuating source of pain and muscle hypotoncity.* Reactive
splinting in the joint’s intrinsic muscles may further accentuate this
process by blocking passive joint movement and the pain-inhibiting
qualities of joint mechanoreceptor stimulation.120 Persistent contractions over time may develop into muscle contractures as a result of
adaptational shortening and loss of elasticity from disuse or underuse. Although there is little direct evidence to support the belief that
sustained muscle contraction is a feature of intervertebral dysfunction, the concept of protective muscle splinting appears plausible.121
Maladies capable of producing acute muscle contraction are wide
ranging; they include trauma, structural inadequacies, visceral disease, emotional distress, and exposure to cold.122,123
Interarticular Derangements. A number of internal joint
derangements have also been submitted as probable causes of
joint locking and back pain. They include internal derangements of the intervertebral disc (IVD; intradiscal block), derangements of the posterior spinal joints (interarticular, intermeniscoid
block),50,51,77,78,130-146 and compressive buckling injuries.12,13 They
are hypothesized to induce mechanical blockage to movement
and unleveling of the motion segment, with resultant tension
on the joint capsule, annulus, or both. The joint capsule and
posterior annulus are pain-sensitive structures, and tension on
these elements may induce additional painful muscle splinting,
further accentuating the mechanical blockage and joint restriction. Mechanical joint dysfunction is therefore considered to be a
�significant and frequent cause of spinal pain and a potential source
of spinal degeneration.
Interarticular Block. One source of derangement of the posterior joints is speculated to result from entrapment (Figure 3-2) or
extrapment (Figure 3-3) of joint meniscoids or synovial folds.131-141
The intra-articular meniscoids are leaflike fibroadipose folds of synovium that are attached to the inner surface of the joint capsule and
project into the joint cavity. These meniscoids have been found to
be present in all of the posterior joints of the spine.
Impinged position
Reduced: hard edge remaining
remodels with time
Reduced
Normal position
A
B
Figure 3-2â•… Theory of meniscoid entrapment. A, Diagrammatic rep-
resentation of meniscoid entrapment inducing flexion and extension
malpositions, capsular tension, pain, and subsequent restrictions in spinal mobility. B, Manipulation of the joint separates the joint surfaces,
allowing the meniscoid to return to a neutral position.
*References 34, 51, 54, 56, 76, 78, 116-119.
A
B
C
D
Figure 3-3â•… Theory of meniscoid extrapment. A, On flexion, the inferior
articular process of a zygapophyseal joint moves upward, taking a meniscoid
with it. B, On attempted extension, the inferior articular process returns
toward its neutral position, but the meniscoid, instead of reentering the
joint cavity, buckles against the edge of the articular cartilage, forming a
space-occupying lesion under the capsule. C, Manipulation gaps the joint
and allowing the meniscoid to return to its neutral resting position (D).
Bogduk and Jull140 have suggested that extrapment of these
meniscoids may be one cause of restricted joint motion. They speculate that the meniscoid may occasionally be pulled out of its resting
position by the inferior articular process of a zygapophyseal joint as it
moves upward during flexion. On attempted extension, the inferior
articular process returns toward its neutral position, but the meniscoid, instead of re-entering the joint cavity, impacts against the edge
of the articular cartilage and buckles, representing a space-occupying
lesion under the capsule. Pain occurs as a result of capsular tension,
and extension motion is restricted. The use of a distractive or joint
gapping adjustive procedure may function to separate the articular
surfaces and release the extrapped meniscoid (see Figure 3-3).140,147
Maigne78 and others77,116,137,148-152 have proposed a model of
interapophysary meniscus entrapment rather than extrapment.
In this model the menisci are purportedly drawn into a position
between the joint margins during poorly coordinated spinal movements or sustained stressful postures. With resumption of normal
postures, pain resulting from impaction of the menisci or traction
of the articular capsule induces reactive muscle splinting and joint
locking. The development of a painful myofascial cycle is initiated
as prolonged muscle contraction leads to muscle fatigue, ischemia,
and more pain. If spasm and locking persist, the articular cartilage
may mold around the capsular meniscus, causing it to become more
rigidly incarcerated within the joint.116-118 To interrupt the cycle of
pain, muscle cramping, and joint locking, distractive adjustments
have also been presented as a viable therapy capable of inducing
joint separation, cavitation, and liberation of the entrapped menisci
(see Figure 3-2).118 It is important to note that meniscoid derangement is only one hypothetical cause of joint dysfunction. Meniscoid
derangement is postulated to be a more likely source of joint dysfunction in circumstances in which trivial trauma leads to acute
joint irritation or locking and associated muscle spasm.139
Interdiscal Block. The mechanical derangements of the IVD
that may lead to joint dysfunction are postulated to result from
pathophysiologic changes associated with aging, degenerative disc
disease, and trauma. Farfan153 has proposed a model of progressive disc derangement based on repetitive rotational stress to the
motion segment. He postulates that repetitive torsional loads of
sufficient number and duration may, over time, lead to a fatigue
injury in the outer annular fibers. The process would begin with
circumferential distortion and separation in the outer annular
fibers, followed by progression to radial fissuring and outward
Chapter 3╅ Joint Assessment Principles and€Procedures |
migration of nuclear material. Another view postulates that disc
derangement, fissuring, and herniation begin in the innermost
annular rings and progresses outward.154
The rate of fatigue and injury depends on the duration and
magnitude of the force applied. In the individual with disrupted
segmental biomechanics, the process is potentially accelerated as
an altered axis of movement leads to increased rotational strain on
the IVD. Postmortem dissection studies of degenerated discs have
indeed identified radial fissures in the annulus fibrosus. Cyriax155
believes that displaced nuclear material along an incomplete fissure is the source of joint fixation. Nuclear migration along these
radial fissures has also been demonstrated by computed tomography (CT) discography and correlated with patient pain.156
Interwoven in the natural history of degenerative disc disease
may be episodes of acute mechanical back pain and joint locking. Maigne78 and others23,129-131 have postulated that incidents of
blockage may occur during efforts of trunk flexion as nuclear fragments become lodged in fissures in the posterior annulus (interdiscal block) (Figure 3-4). Consequently, tension on the posterior
annulus and other mobile elements of the involved motion segment are produced, initiating local muscle guarding and joint locking. Cyriax126 proposes that these lesions may induce tension on
the dura mater, inducing lower back pain (LBP) and muscle splinting. Once local pain and muscle splinting are initiated, a self-perpetuating cycle of pain, cramping, and joint locking may result.
Adjustive therapy has been proposed as a viable treatment for
interrupting this cycle of acute back pain and joint locking. In addition to the distractive effect on the posterior joints, adjustive therapy is thought to have a potential direct effect on the IVD, either by
directing the fragmented nuclear material back toward a more central
position or by forcing the nuclear fragment toward a less mechanically
and neurologically insulting position (see Figures 4-18 and 4-19).
Of course there are spinal joints (atlanto-occipital and atlantoaxial
articulations) that do not have IVDs, and they are common sites of
dysfunction. This clearly indicates that IVD derangement is not the
sole source of spinal joint subluxation or dysfunction.
Compressive Buckling Injury. Triano suggests that a causal
factor for a manipulable lesion may be a compressive buckling
injury.12,13 Intersegmental buckling is likely the result of some error
in neuromuscular control that fails either to provide adequate prestability to the segment or to respond appropriately with muscle
Figure 3-4â•… Interdiscal block. Illustration of nuclear material migrating into internal annular fissures, producing tension on the posterior
annulus.
41
activation to a perturbation.157 When a mechanical overload to
spinal functional units occurs, either as a single traumatic event
or cumulative events, a critical buckling load may be reached.
Individual structural elements (disc, facet, ligament, nerve, muscle) may experience concentration of local stresses with reduced
functional limits and symptom production specific to the tissue
affected. The result is a state of dysfunction that may lead to local
inflammatory or biomechanical changes.158,159
Each joint possesses some inherent stability resulting from
the stiffness of the ligaments and joint capsule. Further stability
and control are provided by the neuromuscular system and faulty
motor control may lead to inappropriate levels of muscle force
and stiffness at a given spinal segment. This may compromise segmental stability at that level,160 leading to transient intersegmental buckling.161 The segment briefly exceeds its safe physiologic
motion, which leads to loading of the surrounding soft tissues
(ligaments, IVD, etc.).157 Furthermore, exposure to vibration and
previous disc injury may augment the buckling event. The result
of intersegmental buckling is asymmetric positioning of the vertebra that is maintained by the intrinsic muscles producing hypomobility of the functional unit.
Clinical Joint Instability and Hypermobility
Joint dysfunction resulting from soft tissue injury or degeneration
does not necessarily result in joint hypomobility. Disturbances of
function of the vertebral column can also result from a loss of joint
stability. Joint derangement and dysfunction resulting from a loss
of joint stability are commonly referred to as joint hypermobility or
clinical joint instability. Both terms are often used interchangeably,
and there is no standard for defining these terms. Definitions vary
among clinicians and authors and between the clinical and biomechanical literature.162,163
Although numerous definitions abound, all seem to incorporate
a loss of stiffness or sensorimotor control affecting the joints’ stabilizing structures.162-165 The loss of stiffness is clinically relevant if excessive or aberrant movements lead to pain, progressive deformity, or
compromised neurologic structures. Movement can be abnormal in
quality (abnormal coupling) or in quantity (increased movement).
Attempts have been made to distinguish clinical joint instability from hypermobility (Table 3-1). The differences are a reflection
of the structures involved and degree of pathologic change in the
joints’ stabilizing structures. Hypermobile joints are assumed to be
stable under normal physiologic loads. Hypermobile joints demonstrate increased segmental mobility, but they maintain normal
patterns of movement. Hypermobility may be in one plane and
not associated with any abnormal translational movements.166,167
In contrast, patients with clinically unstable joints have been
postulated to have ineffective neural motor control or more
advanced changes in the joints’ stabilizing structures.168 Damage to
these structures leads to abnormal patterns of coupled and translational movements and possible multiple planes of aberrant joint
movement. Clinical joint instability should not be equated with
gross orthopedic instability resulting from fracture or dislocation.
There is little doubt that clinical spinal joint instability exists,
but current methods lack the necessary sensitivity and specificity
for clearly identifying its contributions to back pain.162 Clinical
opinion suggests that the typical presentation is one of recurring
42
| Chiropractic Technique
TABLE 3-1
Hypermobility
Instability
Joint Hypermobility versus Instability
Range of Motion
Translational Movements
Coupled Movements
Increased
Increased or normal
Normal ratio
Increased proportion or
aberrant
Normal
Aberrant
episodes of marked back pain, often initiated by trivial events such
as bending or twisting. Global movements are often limited and
may demonstrate a painful arc with abnormal patterns of deviation or hitching. Symptoms often resolve within several days, only
to recur at a later date.165
Physical examination tools are limited but increasing.162,168
Manual palpation of passive posteroanterior glide has been
suggested as one physical means of testing for excessive shear
and instability. One recent investigation did demonstrate that
prone posterior-to-anterior (P-A) passive joint play (JP) evaluation of the spine can accurately identify abnormal segmental
translation as compared with a reference standard of flexion
extension radiographs.169 This test demonstrated good specificity (89%) but poor sensitivity (29%), with a positive likelihood ratio of 2:52. Both the P-A passive segmental mobility
assessment and the prone “instability test” were predictive of
which patients with low back pain (LBP) would benefit from
a lumbar exercise stabilization program.168 The prone instability test requires the patient to lie in a prone position on an
examination table with his or her feet on the floor. The doctor
applies segment-passive P-A pressure and, if pain is produced,
the patient is asked to raise his or her feet off the floor. If pain
is diminished, the test is consider positive and indicative of
segmental instability.
Dynamic flexion-extension and lateral bending radiographs
are the most commonly used radiographic methods for detecting
end-range instability, but they do not provide information about
quality of movement during the midrange of segmental motion.162
Methods using transducers or markers placed over bony landmarks have not demonstrated effective results as a consequence
of the skin motion artifact. Methods using pins embedded in the
spinous processes to measure movement have adequate accuracy,
but these methods are invasive and are not practical for clinical
use.162
In the absence of gold standard diagnostic tools for detecting spinal joint instability, the chiropractor should pay close
attention to the clinical presentation, including history and
manual examination, and consider instability in a patient who
has recurring episodes of back pain with only temporary relief
from manipulation. Suspicion of instability may be reinforced
by dynamic x-ray flexion-extension examination, but this procedure may have false-negative results. When instability is still
suspected, a conservative treatment trial directed at stabilizing
the spine through proprioceptive and specific spinal stabilizing
exercises should be applied.168
*References 15, 26, 33-35, 39, 45, 50-54, 75, 76.
Mechanical Models of Spinal Dysfunction
and€Degeneration
The profession places significant emphasis on the mechanical
components of joint dysfunction and subluxation. Mechanical
joint dysfunction is considered a significant and frequent cause of
spinal pain and a potential source of spinal degeneration.*
The spine is viewed as an interdependent organ system inextricably connected with the rest of the locomotor system. Altered
mechanics in one component of the motion segment are perceived to have unavoidable mechanical effects on other functional
elements of the motion segment and spine. Several models that
outline the proposed sequential dysfunctional and degenerative
effects that may ensue subsequent to spinal dysfunction have been
developed.
Gillet Model. Gillet41-46,53 considers the process of mechanical joint dysfunction developing through three different phases
of joint fixation: muscular, ligamentous, and articular. Muscular
fixation is considered to be a product of segmental muscle hypertonicity and contraction; ligamentous fixations, the product of
contracture and shortening in the joint capsule and its periarticular ligaments; and articular fixations, the product of fibrous interarticular adhesions between articular surfaces. The end stage of
articular adhesions is the potential progression to full bony ankylosis and irreversible fixation.
Muscular fixations are identified by the palpation of taut
and tender muscle fibers and restricted joint mobility. The end
play (EP) is restricted, but has a rubbery and giving quality.
Ligamentous fixations demonstrate restricted joint movement
and a hard, abrupt, leathery end feel. Articular fixations demonstrate the same quality of restriction, but in all planes of motion.
Gillet maintains that ligamentous or articular fixations are the
most significant. He considers muscular fixations as secondary compensations to marked fixations at other levels. As a result, he presents an approach that stresses the identification and treatment of
the patient’s major fixations. Gillet classifies major fixations as those
demonstrating the most dramatic blockages to movement. He contends that the major fixations are frequently not the most symptomatic sites, but are the key to inhibiting pain-free spinal function.
Although his ideas are intriguing and have had a profound effect on
the profession, they have not been experimentally confirmed.
Kirkaldy-Willis’ Model. Kirkaldy-Willis169,170 presents a
pattern of spinal degeneration founded on the principle that
spinal degeneration often begins with local mechanical derangement in the absence of structural alteration. He postulates that
*References 26, 34, 39, 50-54, 56, 75, 167
Chapter 3╅ Joint Assessment Principles and€Procedures |
the process is often initiated with the development of
individual motion segment dysfunction secondary to alteration
in segmental muscle tone and function. Although the disorders
that are postulated to initiate dysfunction are extensive, most
share as a consequence the potential to induce joint hypomobility.26 Joint hypomobility is speculated to initiate the degenerative cycle through the development of altered segmental
biomechanics.*
If mechanical derangement persists, repetitive abnormal loading eventually leads to fatigue and attenuation of the articular soft
tissues. Local joint instability develops as a result of capsular laxity and internal disruption of the IVD.26,170,171 Consequently, if
the derangement is of sufficient magnitude, osseous structural
alteration will result, and degenerative joint disease becomes
radiographically visible (Figure 3-5).170
The final effect of this degenerative cycle is the restabilization of
the joint through soft tissue fibrosis and bony exostosis.26,170 As a
consequence, the incidence of spinal pain may decrease during the
later stages of stabilization. However, bony entrapment of the NRs or
stenosis of the spinal canal are of increasing frequency, which may lead
to an increased frequency of leg pain and neurologic deficits.170,171
The presented models of motion segment degeneration and
the compensational adaptations initiated are not necessarily limited to the involved joint. Not only is it possible for joint hypomobility, instability, and degenerative joint disease all to occur at
the same motion segment, but it is also possible for compensatory
dysfunction and degenerative changes to develop at other spinal
levels or other joints within the �locomotor system.26,34,46,51-53,75
Certainly not all joint dysfunction fits this pattern of progression. A large percentage of dysfunction is self-limiting or so minor
that an individual adapts and compensates to the change with limited structural or functional alteration. If dysfunction persists, the
processes of local and distant joint degeneration may ensue.
A point of emphasis and concern for the chiropractic profession
is therefore to detect persistent mechanical dysfunction at an early
stage of alteration and strive to eliminate it before it develops into
irreversible or permanent disorders.
* References 26, 34, 39, 50-54, 56, 75, 167
FACET JOINTS
Synovitis
hypomobility
Continuing
degeneration
Capsular laxity
Subluxation
Enlargement of
articular processes
43
Neurobiologic Components
Theory of Intervertebral Encroachment and
Nerve€Root€Compression
Historically, the profession has emphasized spinal NR compression as the significant neurologic disorder accompanying vertebral subluxations.1-3,27-38 Spinal subluxations were hypothesized
to induce NR compression as a result of direct anatomic compression of neural elements (non–impulse-based model) within
the intervertebral foramen (IVF) (Figure 3-6). The resulting NR
dysfunction was subsequently hypothesized to induce dysfunction of the somatic or visceral tissues they supplied. Marked or
prolonged compression was hypothesized to induce loss of function. More moderate compression was hypothesized to lead to
increased neural activity and increased pain, paresthesias, and
hypertonic muscles.2,3,27-38
The initial model of direct bony compression of NRs has produced considerable skepticism outside the profession and less
than universal endorsement within the profession.35,38,172 In 1973,
Crelin172 challenged the anatomic plausibility of subluxationinduced NR compression. He conducted cadaveric lumbar dissections, measuring the lateral borders of the IVF, and concluded that
the bony borders of the lateral IVF provided for a minimum of
4 mm of space around each exiting NR. In addition, the NRs gain
a dural covering at their point of entry to the IVF, further reducing
their vulnerability to compression.173,174 He concluded that in the
absence of degenerative joint or disc disease, it was unlikely that
joint subluxation could produce enough narrowing of the IVF to
produce direct anatomic compression of spinal NRs.
In 1994, Giles175 revisited Crelin’s criticism of the chiropractic model of subluxation-induced NR compression. Lumbar
cadaveric dissections were again performed, but this time they
included dissections at the level of the interpedicular zone, not
just at the lateral borders of the IVF as Crelin had performed.
Measurements made at the interpedicular zone demonstrate
an average of 0.4 to 0.8 mm of space around each NR and the
Intervertebral
foramen
INTERVERTEBRAL DISC
Dysfunction
Circumferential
tears
Herniation
Radial tears
Instability
Internal
disruption
Lateral nerve
entrapment
One level
stenosis
Multilevel
spondylosis
and stenosis
Disc resorption
Normal spinal
nerve root
Lumbar
extension
subluxation
Compressed
spinal nerve root
Osteophytes
Figure 3-5â•… The proposed sequence of pathologic changes in the facet
joints and disc as a consequence of biomechanical derangement. (From
Kirkaldy-Willis WH, Bernard TN Jr: Managing low back pain, ed 4,
New York, 1999, Churchill Livingstone.)
Figure 3-6â•… Diagram illustrating lumbar extension subluxation and
theory of subluxation-induced compression of spinal nerve roots as they
exit the intervertebral foramen.
44
| Chiropractic Technique
D
A
PR
AR
P
SN
Figure 3-7â•… Diagram showing the interpedicular zone in a lumbar
motion segment. Contained within the zone are dura mater (D), arachnoid mater (A), the anterior root (AR), pia mater (P), the posterior root
(PR), ganglion, and the spinal nerve (SN). Note the proximity of the
neural structures to the cephalad pedicle. (Modified from Giles LGF: J
Manipulative Physiol Ther 17:4, 1994.)
�
dorsal
root (DR) ganglion (Figure 3-7). These margins are only a
small percentage (10% to 20%) of the space originally described
by Crelin and theoretically small enough to be affected by joint
dysfunction and subluxation. Moreover, his methodology and
conclusions did not account for structural variants such as the
transforaminal ligaments or the presence of functional alterations
such as edema.176
The spinal nerve rootlets at this level lack the epineural covering of the NRs as they exit the IVF and are more susceptible to
pressure, inflammation, and ischemia. The DR ganglia (DRG),
which lie within this space, are especially susceptible to compressive forces,177 and chronically injured dorsal NRs respond more
vigorously to mechanical deformation.178
Furthermore, it is not necessary for spinal NRs to be directly
compressed by bony structures to develop pathologic dysfunction. There are other structures within the IVF (e.g., arteries,
veins, recurrent meningeal nerve, lymphatics, fat, areolar connective tissue) that occupy space, making it possible that other kinds
of mechanical stresses may affect the nerve tissue.25 Sustained
misalignment or inflammation of the spinal motion segment
may stretch or compress the local vascular structures, leading to
disruption of neural blood supply and neuroischemia.35,179 It
has also been demonstrated that mechanical pressures and tensions applied to the spinal segments may create myriad subclinical neurophysiologic alterations ranging from changes in
intraneural protein composition to altered nerve conduction
characteristics.180-183
The density of sodium ion channels in the soma and initial
segment of DRG cells is relatively high, suggesting these regions
may be unusually excitable.184 These properties may render neural tissue within the IVF vulnerable to effects of mechanical
compression and the chemical environment produced by changes
in the IVD or facet joints.185 Substantial evidence demonstrates
that the DRs and DRG are more susceptible to the effects of
mechanical compression than are the axons of peripheral nerves
because impaired or altered function is produced at substantially lower pressures.185,186 Whether spinal manipulation can
alter neural function by mechanically changing compressional
pressures or reducing the concentration of metabolites in the IVF
is unknown.187
Compression studies investigating how herniated IVDs affect
NR function have been performed. The mechanism by which a
herniated disc could directly compress the DRs or DRG is well
understood and straightforward.187 However, a herniated IVD
could also affect NR function through indirect effects mediated
by the release of neuroactive chemicals.188 This explains the common observation that in the absence of compression, herniated
discs can produce neurologic findings. Recent studies demonstrate that the application of nucleus pulposus to a lumbar NR
causes mechanical hyperalgesia in the distal limb and causes swelling in and decreased blood flow to the DRG.189,190 In addition,
phospholipase A2, an inflammatory mediator associated with disc
herniation188,191 is neurotoxic in high doses to afferent nerves.192
In moderate doses it increases mechanical sensitivity of the DRs,
producing long-lasting discharge, and it increases the discharge of
previously silent DRG cells.192,193
The intervertebral canal and each of its motion segments
have a vascular supply composed of spinal arteries and veins.
The spinal arteries provide oxygenated blood to the spinal cord
and dorsal and ventral NRs. Blood vessels are softer and more
susceptible to the effects of stretch and compression than are the
nerves they supply, making localized neuroischemia, without
direct compression, a possible result of spinal joint dysfunction.
If joint malposition does contribute to dysfunction of the spinal NRs, it is more likely to occur by narrowing the more vulnerable interpedicular zone. Furthermore, joint subluxation has a
greater potential to affect NR function if it is secondary to other
disorders that have already led to narrowing of the lateral recess,
such as disc herniation or other space-occupying lesions, degenerative disc and joint disease, and joint instability.
Although recent anatomic investigations have provided a plausible mechanism by which joint subluxation may contribute to
NR dysfunction, it still remains a tenuous theory. The clinical
literature has established that encroachment of neural structures
within the IVF may produce NR dysfunction, but it has not established whether spinal subluxations alone (i.e., without other neurocompressive sources) can cause encroachment and altered neural
activity. Furthermore, it must be appreciated that a subluxation
occurs within the normal ROM for the segment. The IVFs of each
segment change size and shape with movements. Extension combined with rotation and lateral flexion to the same side maximally
decreases the opening of the IVF, yet no NR compression occurs.
Therefore, something in addition to a sustained malposition has
to occur to produce clinical signs of NR compression, such as
inflammation, disc deformation, or vascular changes.
In conclusion, it appears that the early “foot-on-the-hose”
model of joint subluxation and NR compression is not biologically plausible. Joint subluxations alone are extremely unlikely to
“pinch” the spinal NRs at the margins of the IVF.
Chapter 3╅ Joint Assessment Principles and€Procedures |
Theory of Altered Somatic and Visceral Reflexes
Somatosomatic and Somatovisceral Reflexes. In the absence
of evidence to confirm the NR compression hypothesis, the
�profession has assembled an alternative model of subluxation
Â�syndrome–induced neurologic alterations (impulse-based model).
The impulse-based paradigm of neurodysfunction has been developed from the work of Homewood and Korr.32-35,37-39,194
A somatoautonomic reflex is elicited when stimulation of somatic
tissue (the musculoskeletal system and the dermis of the skin) is
manifested as an alteration in autonomic nervous system function.
A spinal visceral reflex is a type of somatoautonomic reflex in which
stimulation of the spinal column alters visceral function.195
This hypothesis envisions vertebral joint dysfunctions as lesions
capable of inducing chronically altered nociceptive and proprioceptive input. This persistent afferent input, driven by mechanical alteration, pain, and potential local inflammation, triggers a
segmental cord response, which in turn induces the development
of pathologic somatosomatic or somatovisceral reflexes. The persistent altered afferent input is then theorized to produce sensitization of local spinal neuron pools and the establishment of
abnormal somatosomatic or somatovisceral reflexes. The reflexes,
once established, become the potential driving source of altered
somatic or visceral function. If these reflexes persist, they are
hypothesized to induce altered function in segmentally supplied
somatic or visceral structures.32-35,37-39,56,196-198
Thus joint subluxation/dysfunction syndrome (JSDS) may
initiate secondary dysfunction in tissues with shared segmental
innervation. Indeed, clinical investigations have demonstrated
that altered muscle tone, deep tendon reflexes, and altered sympathetic activity may accompany joint derangement and dysfunction.199-203 Many of these findings had been previously assumed to
be associated with NR dysfunction only. The segmental muscle
hypertoncity that may be associated with joint dysfunction illustrates a clinical example of a somatosomatic reflex; cervical disequilibrium secondary to cervical joint dysfunction illustrates an
example of a somatovisceral disorder (Figure 3-8).201
4
Visceral
afferent
2 1
2
Afferent
from joint
Efferent
blood vessels
3
45
The proposed joint subluxation- or dysfunction-induced neurologic phenomena may be clinically manifested by the presence of
referred pain, hypertonicity, hyperesthesia, or altered sympathetic
activity, such as altered temperature regulation and skin conductance.199-203 Manual therapy, including soft tissue techniques and
other forms of adjustive therapy, would have the potential for
arresting both the local and distant somatic and visceral effects
by terminating the altered neurogenic reflexes that are associated
with somatic or joint dysfunction.
Viscerosomatic (Autonomic) Reflexes. Persistent pathologic
conditions in visceral structures also have the theoretic potential
to induce reflexive dysfunction in other somatic or visceral structures. Visceral disease or dysfunction may activate the autonomic
nervous system through connections with the lateral horn cells
in the cord to produce vasomotor, trophic, visceral, or metabolic
changes (see Figure 3-8). Numerous conditions have been linked
to hyperactivity of the sympathetic nervous system; these include
various types of cardiovascular, gastrointestinal, and genitourinary
disorders, and certain musculoskeletal disorders such as complex
regional pain syndrome.
It has been suggested that the body wall manifestations of
visceral disease are an integral part of the disease process, rather
than just physical signs and symptoms,204 although the definitive
causal factors and the characteristic response of the individual are
still unknown. Early signs of most disease states are manifested as
symptoms and signs that are part of a common reaction pattern to
injury or stress. Pain in the somatic tissues is a frequent presenting symptom in acute conditions related to visceral dysfunction.
Palpatory cues of transient muscle hypertonicity and irritation or
subcutaneous edema may be accompaniments of ill-defined subclinical states.205 Moreover, subtle changes in tissue texture, joint
position, and joint mobility identified by discerning palpatory
skills may at times be latent manifestations of the somatic component of visceral disease.
In a study performed on cardiac patients in an intensive care
unit,206 autonomic spinal reference changes were noted for the
involved viscera (Box 3-2). In studies by Kelso,207 it was noted
that as the visceral condition progresses, the somatic stress pattern
subsides, and a typical visceral reflex pattern is seen. Therefore, the
chronic phase of reflex activity is characterized by trophic changes
in the skin and subcutaneous tissues, as well as local muscle contraction. This may result in a joint misalignment and decreased
segmental mobility. However, it is not known whether the continuation of reflex somatic dysfunction is related to the initial effect
of the visceral disease or whether it is a result of �long-term segmental facilitation.
Visceral
efferent
Efferent
to muscle
Figure 3-8â•… Afferent pathways from the somatic and visceral structures can produce somatosomatic (1), somatovisceral (2), viscerosomatic
(3), and viscerovisceral reflex phenomena (4).
BOX 3-2
utonomic Changes in Soft Tissues
A
Identified in Patients with Viscera Problems
Vasomotor reaction—increase in skin temperature
Sudomotor reaction—increase in skin moisture
Increase in muscle tone and contraction
Skin texture changes—thickening
Increased subcutaneous fluid
46
| Chiropractic Technique
In a blind study of 25 patients, Beal208 was able to �differentiate
patients with cardiac disease from those with gastrointestinal
�disease with a reported accuracy of 76% using a compression
test to examine for soft tissue texture changes and resistance to
segmental motion. Similarly, Beal and Dvorak209 examined 50
patients in a physician-blind format and were able to identify
characteristics specific for patients with cardiovascular, �pulmonary,
�gastrointestinal, or musculoskeletal diseases.
In summation, it is apparent that spinal dysfunction has the
potential to both produce and be the product of visceral or somatic
dysfunction or disease. The literature supports the �existence of
somatovisceral and viscerosomatic reflexes,210-212 but there is little
or no evidence to support the notion that the VSC can cause prolonged aberrant discharge of these reflexes. Also unsupported in
the literature is the notion that the prolonged activation of these
reflexes can induce pathologic change and visceral disease. Nor does
the literature support the position that spinal manipulative therapy
can alter the prolonged reflex discharge to an extent that induces a
reversal of the pathologic degeneration of the affected tissues.213,214
Although there have been investigations using animal models on
the effects of mechanical stimulation of the spine on blood pressure, heart rate, and renal sympathetic nerve activity,215-220 unfortunately there is almost no physiologic research concerning responses
in humans to either spinal pain or innocuous mechanical stimulation. Furthermore, most of the data obtained were elicited with
noxious stimulation. There is still little support for the contention
that painless spinal dysfunction can affect organ function, which is
not surprising, considering that all the basic physiologic work cited
was performed on anesthetized animals. The evidence does suggest
that muscle spindles in cervical paraspinal muscles may in fact be
capable of eliciting somatoautonomic reflexes.221
The complex interrelationship of the NMS system demands
that chiropractors and other manual therapists be open to the
numerous potential sources of their patients’ complaints. Spinal
pain and dysfunction may be secondary to a disorder that is not
amenable to manual therapy. In circumstances in which JSDSs are
secondary to active visceral or somatic disease, manipulative treatment alone would be inappropriate.
Inflammatory and Vascular
Components
Joint injury, chronic mechanical joint derangement, or joint
immobilization may initiate the inflammatory and vascular components of the VSC.34,54,56,75 These components include vascular
congestion, ischemia, and inflammation.
Vascular Congestion
It is unclear at this time what role, if any, spinal segmental function or dysfunction plays in local vascular congestion. Speculation
has centered on the potential for motion segment dysfunction or
associated inflammation to impede blood flow through segmental
venous structures. Venous pressure is very low and depends on gravity in the spinal veins, making them quite susceptible to compression and venous congestion. Lantz suggests that immobilization
may lead to localized venous stasis, creating a negative pressure and
lack of proper venous drainage that may lead to inflammation.222
Figure 3-9â•… The internal and external systems for segmental venous
drainage. (From Kirkaldy-Willis WH, Bernard Jr TN: Managing low back
pain, ed 4, New York, 1999, Churchill Livingstone.)
A segmental vein drains each motion segment and related
spinal canal. Each segmental vein receives venous blood from an
extensive internal venous plexus (Batson), which in turn receives
blood from a basivertebral vein that drains each individual vertebra
(Figure 3-9). The intraspinal venous plexus is located within the
epidural space and basically consists of two paired columns that
are united via a transverse communication vein. A lack of venous
drainage in these structures is speculated to lead to increased capillary pressure, diminished arterial blood flow, and the production
of local ischemia, inflammation, and potential associated joint
stiffness.223 In addition, a tear in a fragile vein may occur, possibly as a result of repetitive increases in intra-abdominal pressure,
producing a hematoma that serves as a space-occupying lesion.
Because the veins course vertically at the posterolateral aspect of
each disc bilaterally, they can produce the same clinical picture as
a disc herniation as they expand. The only differentiating test is
magnetic resonance imaging (MRI), using T2-weighted images to
visualize more water content in the blood-filled hematoma.
Inflammatory Reactions
Inflammatory reactions are largely mediated by the vascular system and accompanied by cellular and humoral components that
act as an intrinsic source of pain and vasodilation.224 The inflammatory reaction initiated by musculoskeletal injury or dysfunction is identical to that initiated by a foreign object or infection.
Although it is a normal protective response, it may accentuate the
pain response, slow the recovery time, and perpetuate joint dysfunction. Pain accompanying inflammation may initiate local
reflex muscle contraction, which, over time, may lead to local ischemia and potentially more pain and muscle splinting. The result,
as described previously, is a self-perpetuating cycle of pain and
continued muscle spasm.* If the muscle contraction persists,
it may eventually develop into a muscle contracture as the
*References 34, 51, 54, 56, 76, 78, 116-119.
Chapter 3╅ Joint Assessment Principles and€Procedures |
myofascial structures become shortened and infiltrated with
fibrotic �tissue.170,225 The resulting soft tissue derangements and
contractions that develop must be dealt with therapeutically, or
they will serve as a source of continued pain and recurring joint
subluxation and dysfunction.
With persistent inflammation and pain, plastic changes may
occur in the peripheral and central nervous systems that lower
pain thresholds, giving rise to allodynia (pain in response to a normally innocuous stimulus), hyperalgesia (heightened pain intensity in response to a normally painful stimulus), and sensitization
of the central nervous system. Afferent nerve fibers that are quiescent in normal joints may become active and start to send nociceptive information to the central nervous system, which can also
become sensitized to perceive what is typically nonpainful stimuli
as painful.226-228
In addition, chronic joint inflammation may lead to synovial
tissue hyperplasia and thickening as a result of persistent irritation
and secretion of synovial fluid.229,230 Synovial tags may develop
as a hyperplastic reaction to chronic inflammation, and they in
turn may become further impediments to joint movement.225,231
Eventually, fibrous invasion of the synovial connective tissue layer
may induce an attendant loss of vascularity and subsequent loss of
synovial fluid secretion.148
Some degree of joint or soft tissue inflammation should be suspected when the patient’s pain is constant. Clinical signs include
muscle splinting, soft tissue swelling, and temperature alteration.
Inflammation associated with spinal joint injuries or dysfunction
is unlikely to produce palpable swelling at the surface. Some have
suggested, however, that joint dysfunction may be associated with
a local sympathetic reflex alteration capable of inducing a slight
boggy feeling in overlying segmental tissues.
JOINT SUBLUXATION/DYSFUNCTION
SYNDROME
A Joint Subluxation/Dysfunction Syndrome (JSDS) diagnosis is
a clinical diagnosis defined by an aggregate of signs and symptoms that are assumed to identity dysfunction of spinal, pelvic, or
peripheral joints.232,233 It is a functional (biomechanical) diagnosis,
not a structural (pathoanatomic) diagnosis. When applied to the
spine, it implies that the spinal motion segments and their associated soft tissues are the source of the patient’s symptoms. Unlike
traditional structural diagnoses like disc derangement, sprain or
strain, and spinal stenosis, the diagnosis of JSDS does not attempt
to identify specific tissue pain generators within the spinal motion
segment. This diagnosis typically includes local axial spine pain
reproduced or accentuated by static or dynamic palpation. It
may be associated with sclerogenic referred pain into the proximal extremity. The diagnosis of JSDS usually denotes to chiropractic physicians that the condition may be amenable to manual
therapy; high velocity–low amplitude (HVLA) adjustive therapy
is most commonly applied treatment.
Joint dysfunction may occur in isolation, but is commonly
associated with other identifiable functional and pathoanatomic
disorders and conditions. The individual chiropractor and the
profession as a whole should make every attempt to incorporate
these diagnoses in assessment and patient management.
47
SPINAL LISTINGS
As the chiropractic profession has evolved, it has developed various abbreviated descriptions for designating abnormal joint position or movement. The result is a profession laden with redundant
nomenclatures (listing systems) that describe spinal subluxations
and fixations. As new descriptive terms are introduced, old ones
are not replaced. It is not uncommon for each technique to have
its own unique listing system. Unique listing methods may be efficient for those performing the associated technique, but many are
not commonly understood.
As part of the process to include chiropractic in Medicare, there
was an attempt to standardize listing systems at the 1977 American
Chiropractic Association (ACA) conference in Houston. Although
the parties did succeed in developing a common nomenclature for
Medicare claims based on standard kinesiologic terms, it unfortunately did not form a basis for larger professional consensus. There
is still significant variation among chiropractors and on national
board examinations as to the preferred listing systems.
To their students’ continual frustration, colleges are left in a
position of teaching repetitive and often contradictory methods of
describing joint malpositions and fixations. Presently, the common
systems used to describe abnormal position are Medicare, PalmerGonstead, and National–Diversified systems. In an attempt to reduce
the confusion and redundancy, this book emphasizes standard kinesiologic terms and the Medicare listing system. When deviations in
position are described, the term malposition is used, and when limitations to movement are described, the term restriction is used.
Spinal joint listing systems should be incorporated only in conjunction with a diagnosis of spinal JSDS. They describe characteristics of subluxation and dysfunction syndromes, but they are not
expected to be stand-alone diagnostic terms. Spinal listings should
be viewed only as a short-hand method of recording which joint
changes were subjected to manipulation (Figure 3-10).
All motion segment malpositions are described with the position of the upper vertebra compared with the lower vertebra. For
example, a flexion malposition describes a vertebra that has deviated into a position of flexion relative to the vertebra below, and
a flexion restriction describes a limitation or loss of joint flexion
between the two vertebrae.
Trunk and neck movements are described in kinesiologic terms.
They are based on vertebral body movement, not spinous process
movement. Left rotation of the trunk is defined by left posterior
vertebral body rotation, not by right rotation of the spinous process.
CLINICAL EVALUATION OF JOINT
SUBLUXATION/DYSFUNCTION
SYNDROME
Before adjustive treatments are applied, the chiropractor must
evaluate the patient’s complaint and determine if the patient is
suffering from a condition (manipulable lesion) that is amenable
to chiropractic care. As mentioned previously, therapeutic decisions on where and how to apply adjustive therapy are based primarily on the evaluation of the NMS system and a determination
that injury, derangement, or disease has led to altered function.
48
| Chiropractic Technique
Although the diagnosis of joint dysfunction identifies a painful
clinical syndrome that may respond to manual therapy, the nature
of the dysfunction must be evaluated before therapy is administered. The mere presence of joint subluxation or dysfunction does
not determine the need for adjustive therapy. Joint �dysfunction
may result from diseases or disorders that contraindicate treatment or result from disorders that do not respond to adjustive
treatments. The ability to thoroughly evaluate and triage disorders of the NMS system and distinguish those conditions that
are appropriate for chiropractic care is critical. Differentiating
Medicare
(Vertebral body reference)
Palmer-Gonstead
(Spinous process reference)
National-Diversified
(Vertebral body reference)
Flexion malposition
None
Anterior inferior
Extension malposition
Posterior
Posterior inferior
Right lateral
flexion malposition
None
Right inferior
Left lateral
flexion malposition
None
Left inferior
Left rotational malposition
Posterior spinous right
Left posterior
Right rotational malposition
Posterior spinous left
Right posterior
Anterolisthesis
None
Anterior
Retrolisthesis
Posterior
Posterior
Right lateral listhesis
None
Right lateral
Figure 3-10â•… Comparative chart of static listing systems. (Modified from ACA Council on Technic: J Am Chiropr Assoc 25[10]:46, 1988.)
Chapter 3╅ Joint Assessment Principles and€Procedures |
Medicare
(Vertebral body reference)
Palmer-Gonstead
(Spinous process reference)
National-Diversified
(Vertebral body reference)
Left rotational malposition
Left lateral
flexion malposition
Posterior right
Superior spinous
Left posterior inferior
Left rotational malposition
Right lateral
flexion malposition
Posterior right
Inferior spinous
Left posterior superior
Right rotational malposition
Right lateral
flexion malposition
Posterior left
Superior spinous
Right posterior inferior
Right rotational malposition
Left lateral
flexion malposition
Posterior left
Inferior spinous
Right posterior superior
Dynamic (motion) listing: designation
of abnormal joint movement
Restriction: direction of limited
movement in subluxated
dysfunctional joints
Extension
restriction
Flexion
restriction
Right rotational
restriction
49
Dynamic listing nomenclature
1. Flexion restriction
2. Extension restriction
3. Lateral flexion restriction (right or left)
4. Rotational restriction (right or left)
Left rotational
restriction
Right lateral
flexion restriction
Left lateral
flexion restriction
Figure 3-10—Cont’d
mechanical from nonmechanical conditions, assessing the source
of the presenting complaint, and understanding the potential
pathomechanics and pathophysiology of the disorders being considered for chiropractic care are crucial elements for successful
treatment. Therefore, before instituting treatment, the clinician
must perform a thorough case history, physical examination,
and any other appropriate imaging or laboratory procedures to
rule out any disorders that contraindicate adjustive treatments.
The evaluation should assess whether the dysfunction is associated with joint hypermobility or hypomobility and the site, side,
and potential directions of immobility, aberrant movement, or
hypermobility.
50
| Chiropractic Technique
Examination Procedures and
Diagnostic Criteria
Uncomplicated JSDS is a clinical diagnosis identified by a collection of presenting symptoms and physical findings. It is not independently detectable by laboratory procedures, and a single gold
standard for detecting primary joint subluxation or dysfunction
does not currently exist. Often it is suspected after the possibilities
of other conditions with a similar presentation have been eliminated. A favorable patient response to manipulation or mobilization (decreased pain or improved function) and reduction or
normalization of abnormal physical findings indicates the original
working diagnosis and application of manual therapy was a clinically sensible and effective approach.
History
JSDS is commonly symptomatic but the diagnosis does not
depend on the patient being symptomatic. However, in asymptomatic JSDS, one would expect the physical findings supporting the diagnosis to be pronounced. In the spine, patients with
JSDS commonly complain of pain located in the midline to
paraspinal region with or without pain referral into the extremities. Although the somatic referred pain does not usually extend
below the knee or upper arm, pain may radiate as far as the foot
or hand. However, the location, quality, and referral patterns
of the patient’s pain complaints are not unique to this diagnosis. These symptoms overlap with a number of other axial
spine complaints and do not differentiate JSDS from other
mechanical spine disorders. The patient’s history is also crucial
in identifying possible red flags and differentiating nonspecific
mechanical back pain from nonmusculoskeletal or nonmechanical NMS disorders. It is also helpful in implicating neurologic
involvement and identifying mechanisms of possible injury and
load sensitivities pertinent to JSDS.
Physical Examination
With the exception of radiographic evaluation, the majority of the commonly used examination procedures devoted to
assessing joint structural and functional integrity are physical examination procedures. They include standard orthopedic, neurologic, and physical examination procedures and
a wide array of unique “system technique” diagnostic procedures. Observation and palpation are the most commonly used
physical examination procedures and include postural and gait
evaluation, soft tissue and bony palpation, global ROM, and
segmental ROM testing or what is also referred to as passive
intervertebral motion tests.55,74,234-239 Manual palpation is the
primary evaluative tool, necessitating many hours of practice
and concentration to develop adequate skill. The application
of joint manipulation relies heavily on the clinician’s ability to
locate and identify landmarks, painful musculoskeletal tissue,
painful joint movements, contracted muscles, restrictions of
motion, and hard EP resistance.240
Specialized laboratory procedures, such as thermography and
electromyography (EMG), are presently not in common clinical use for detection of JSDS. Further research is necessary before
their role in clinical practice can be fully ascertained. The classic
physical signs indicative of JSDS are provocation of pain, abnormalities in alignment, abnormal resistance to joint movement,
and altered tissue texture. Bergmann,241 modifying the acronym
PARTS from Bourdillon and Day,242 identifies the five diagnostic categories commonly applied by chiropractors for the identification of joint dysfunction: pain and tenderness; asymmetry;
ROM abnormality; tone, texture, and temperature abnormality;
and special tests. Various investigators have suggested that detection of the spinal manipulative lesion should not rely on a single
assessment method.
During spinal evaluation, the physical examination should
focus on identifying the source of the patient’s complaints and differentiating segmental from nonsegmental sources. The examination findings supportive of a spinal JSDS diagnosis can be divided
into primary and secondary categories and are listed in Box 3-3.
It is recommended that the physical assessment of JSDS focus on
reproducing the patient’s joint pain with palpation and joint provocation and challenge procedures. Although a number of manual
examination findings have historically purported to confirm this
disorder, bony and paraspinal soft tissue tenderness or pain reproduced with JP or EP are the most reliable and potentially valid
diagnostic tools.243-246
It has been suggested that tests should be considered in groupings leading to a multidimensional approach.247-251 A 2006 literature review by Stochkendahl and associates concluded that
a “global assessment” (i.e., segmental static and motion tenderness, palpatory altered joint motion, and palpable tissue changes)
demonstrates reproducible intraexaminer reliability (0.44 kappa).
However, there was not enough evidence to calculate pooled
results for interexaminer reliability. The significance of a multidimensional approach is further illustrated by the Health Care
Financing Administration requirement that the manipulable
lesion be supported by physical examination.252 From the initial coverage of chiropractic care in the Medicare program in
1974–1999, Medicare required x-rays to demonstrate subluxation
of the spine and therefore the clinical necessity for chiropractic
care. Beginning in 2000, Medicare allowed physical examination
findings (the pain and tenderness, asymmetry or misalignment,
ROM abnormality, and tissue or tone changes [PARTs] multi�
dimensional approach) for the demonstration of subluxation in
place of x-rays: To demonstrate a subluxation based on physical
examination, two of the four criteria mentioned under “physical
examination” are required, one of which must be asymmetry/misalignment or ROM abnormality.252
Pain and Tenderness
The perception of pain and tenderness is evaluated in terms of location, quality, and intensity. Most primary musculoskeletal disorders
manifest by a painful response. The patient’s description of the pain
and its location is obtained. Furthermore, the location and intensity
of tenderness produced by palpation of osseous and soft tissue are
noted. Pain and tenderness findings are identified through observation, percussion, palpation, and provocative orthopedic testing.
The patient’s description and location of pain is obtained verbally,
physically, or by a pain drawing. The location and intensity of
�tenderness produced by palpation of osseous and soft tissues is
identified and noted. Changes in pain intensity can be �objectified
Chapter 3╅ Joint Assessment Principles and€Procedures |
BOX 3-3
51
Physical Examination Findings Supportive of Spinal Joint Subluxation/Dysfunction Syndrome Diagnosis
Primary Findings
Palpable segmental bony or soft tissue tenderness/
dysesthesia
Painful or altered segmental mobility testing
Joint motion is traditionally assessed in its open packed position with joint play (JP) procedures, through its segmental
range of motion, and with end play (EP) at the end range of
motion. All three components of joint motion are evaluated
for quantity, quality, and pain response. Clinical studies indicate that JP and EP are more reliable for pain response than
range of motion assessment.
Palpable alterations in paraspinal tissue texture or tone
Tissues texture changes are represented by a loss of paraspinal
tissue symmetry at the segmental level or between adjacent
segments. These changes are characterized by palpable alterations in muscle resting tone (hypo or hypertonicity or spasm)
and textural changes characterized by a palpable sense of tissue induration or fibrosis often described as a hardening or
thickening of tissue.
using visual analog scales, algometers, and pain questionnaires.
The production of palpatory pain over osseous and soft tissues has
been found to have good levels of interexaminer and intraexaminer reliability.244,246,253-256 The validity of motion palpation or pain
reproduction with palpation to identify painful spinal joints or
direct effective treatment is limited. The results have been mixed
but encouraging in a few studies.257-262 Although assessment of
segmental motion has generally scored poorly in terms of reliability, in several studies lumbar P-A mobility assessment did succeed
in achieving acceptable predictor scores (likelihood ratios) for classifying and directing various types of therapies (e.g., manual therapy vs exercise).263,264 In these studies P-A mobility testing was
only one of several presentations or physical findings used to categorize patients, and P-A mobility testing may not be a materially
contributing factor in predicting outcome.
Asymmetry
Asymmetric qualities are noted on a sectional or segmental level.
This includes observation of posture and gait, as well as palpation for
misalignment of vertebral segments and extremity joint structures.
Asymmetry is identified through observation (posture and gait analysis), static palpation for misalignment of vertebral segments, and
evaluation of static plain-film radiographs for malposition of vertebral segments. The complex structure of the human body, and especially its frame, is never completely or perfectly symmetric. Therefore,
focal changes in symmetry may or may not be clinically significant.
They must be judged by the degree of deviation and placed within
the context of the overall clinical presentation and examination.
Range-of-Motion Abnormality
Changes in active, passive, and accessory joint motions on a segmental and sectional basis are noted. These changes may be reflected
Secondary Findings
Palpable malposition (e.g., spinous deviation)
Note: Because of individual variation and the high prevalence of asymmetry many manual therapists do not consider
this an indicator of joint dysfunction
Repetitive loading in direction of EP restriction may improve
symptoms
Alterations in sectional or global range of motion:
Decreased and painful global active range of motion
and various positive pain-provoking orthopedic tests
are not primary features of a joint dysfunction diagnosis
because of their commonality with multiple painful
musculoskeletal disorders. Note: active range of motion
may be normal with joint dysfunction syndrome because
of the spine’s ability to compensate at other segmental
levels.
by increased, decreased, or aberrant motion. It is thought that a
decrease in motion is a common component of joint dysfunction.
Global ROM changes are measured with inclinometers or goniometers. Segmental ROM abnormalities are identified through the
procedures of motion palpation and stress x-ray examination.
Tone, Texture, and Temperature Abnormality
Changes in the characteristics of contiguous and associated soft
tissues, including skin, fascia, muscle, and ligaments, are noted.
Tissue tone, texture, and temperature (vasomotor skin response)
changes are identified through observation, palpation, instrumentation, and tests for length and strength.
Special Tests
The category of special tests includes two major subsets. One group
incorporates testing procedures that are specific to chiropractic technique systems, such as specific leg length tests (e.g., Derifield) and muscle tests (e.g., arm fossa test). The other group encompasses laboratory
procedures such as x-ray examination, EMG, and thermography.
System technique assessment procedures are typically manual examination procedures. They are commonly the products of
�individual innovation. They are distinguished from other physical
examination procedures by their unique use and association with brandname �techniques. Most of these procedures have not been subjected to
�testing, and their reliability and validity have not been evaluated.
Many of the laboratory procedures that are promoted as potential detectors of JSDS have substantiated value in evaluating disorders of the NMS system. However, most have not been subjected to
in-depth evaluation relative to their ability to detect segmental joint
dysfunction. In addition, visceral relationships are considered (e.g.,
evaluation of the upper thoracic spine in cases of asthma) in localizing the spinal segment or segments that might be dysfunctional.
52
| Chiropractic Technique
Clinical Usefulness of Joint
Assessment Procedures
Although the effectiveness and appropriateness of chiropractic
adjustive therapy for treating mechanical neck and back pain has
been demonstrated (see Chapter 4), the clinical value and usefulness of many of the diagnostic procedures used to detect JSDS
have not been thoroughly or properly evaluated.236,244,253,256,265-272
The clinical usefulness of a diagnostic procedure is measured by
its ability to provide accurate information that leads to appropriate and effective management of health care problems. These attributes can be evaluated by assessing a given procedure’s reliability,
validity, responsiveness, and utility.
Chiropractic is not alone in its need to advance the critical
appraisal of its diagnostic and therapeutic procedures.273-277 Other
health disciplines also suffer from significant variations in the use
of diagnostic tests, and many lack experimental evaluation and
confirmation.278 The prudent practitioner should remain skeptical of unsubstantiated and biologically unfeasible claims, but
supportive of and open-minded toward investigation of untested
procedures. Untested procedures are not necessarily invalid procedures. It is just as wrong to reject a therapeutic procedure because
it is untested as it is to accept the same procedure in the absence
of supporting evidence.
It is likely, however, that examination procedures that depend
on human evaluation will always carry the potential for some error.
Furthermore, quantifying a manual art is difficult because of the
lack of a standard for comparison.240 The chiropractic doctor must
be aware of these limits, yet constructively use the physical evaluation to help gain the patient’s confidence and compliance. Physical
examination procedures placed within proper clinical perspective
still provide a significant cost-effective contribution to the formation of a clinical impression. Within this context, it is important
not to rely excessively on any one procedure, but rather to use a
combination of diagnostic procedures and allow the weight of evidence to build a clinical impression of the patient’s problem.
Reliability
“Reliability is the reproducibility or consistency of measurement
or diagnosis. It is the extent to which a test can produce the same
result on repeated evaluation of an unchanged characteristic.”271
Reliability estimates the contribution a given test makes to the
clinical decision-making process beyond what would be expected
by chance. Reliability measures include evaluation for interexaminer and intraexaminer consistency, and test-retest evaluation to
determine if measurements are reproducible and consistent over
time. Fortunately, the profession has witnessed a significantly
increased interest in evaluating its diagnostic procedures. It is now
possible to make some generalizations about the reliability of common chiropractic diagnostic procedures.
In 1991, Haas265 reviewed the literature on the reliability of
chiropractic joint assessment procedures and concluded that
many of the studies had questionable design and statistical analyses. These same conclusions have been echoed repeatedly since
then.243,244,256,279-284 In addition, most of the studies evaluated the
reliability of only one procedure at a time. This leaves the question of combined �reliability in need of further evaluation; the
�
procedures
may demonstrate higher reliability when used in conjunction with each other.244,245,253,285,286 Furthermore, combining different assessment methods in a multitest regimen more
closely parallels actual clinical practice.262,286 There are a number
of retrievable studies investigating the utility of multidimensional
evaluation procedures.256,286-291 Only one primary study showed
any reliability approaching acceptable levels, and that varied
from marginal to good.256 A systematic review conducted in 2006
implied that multitest regimens did appear to demonstrate acceptable intraexaminer reliability.244 Based on the available research, it
has to be concluded that there is insufficient evidence to determine the level of interexaminer reliability of a multidimensional
manual examination procedure for detecting manipulable lesions.
Certainly �further research is �warranted to better investigate a
�multidimensional approach.
Validity
Reliability testing is critical, but it is only one element in the process of assessing the clinical value of diagnostic procedures and it
must not be confused with validity. The accuracy, or validity, of a
procedure, or the degree to which the test actually evaluates what
is intended, is of paramount importance.271 Valid health care procedures are those that are useful in helping heath care providers
make accurate and effective heath care decisions.
Although reliability testing for chiropractic joint assessment
procedures has expanded significantly in the last several decades,
validity testing remains in its infancy. Most chiropractors and
manual therapists accept the face validity of common joint assessment292 procedures, but most procedures have not been subjected
to rigorous experimental evaluation. Face validity is a measure of
a diagnostic procedure’s plausibility (biologic reasonableness) to
evaluate a known phenomenon.
Experimental evaluation of diagnostic procedures is necessary
to establish their true merit in accurately identifying a given disorder. Experimental evaluation of validity can be broken down
into construct-based and criterion-based validity assessments.
Construct validity attempts to measure the accuracy of a procedure when a reference standard is not available. Construct validity measures “the ability of a test to perform up to the standards
predicted from a theoretical model or construct.”293
Hass and colleagues↜293 illustrate an example of construct validity
evaluation in their assessment of joint motion palpation. Motion
palpation theory assumes that EP restriction is a palpable indication for thrust manipulation and that immediate postmanipulative restoration of motion should be palpable in some cases.
Therefore, the construct validity of motion palpation for the
assessment of EP and manipulable subluxation and dysfunction
could be assessed by testing the examiner’s ability to identify EP
restrictions and discern if improvement in EP restriction occurs
after thrust manipulation.
Criterion-based validity testing allows the evaluation of a
diagnostic procedure as it compares with a known gold and
coworkers standard procedure.294 The glucose tolerance test is
an established criterion for substantiating blood glucose levels.
This test could therefore be used as the standard for comparing
new tests. There is no established gold standard test for identifying JSDSs.
Chapter 3╅ Joint Assessment Principles and€Procedures |
Responsiveness
The responsiveness of a diagnostic procedure measures its ability
to respond to changes in the condition or phenomenon it is assessing. For a testing procedure to be effective in this category, it must
demonstrate the ability to change with the entity being evaluated. If a given testing procedure is responsive, it has the ability to
reflect improvement or worsening in the condition or function it
is measuring. Responsive tests are valuable in measuring the effects
of treatment and therefore are effective outcome measures.
Utility
Test utility represents the practical usefulness of a diagnostic test.
Clinical utility measures the health benefits provided by a given
procedure. It represents the value the procedure has in directing
effective patient care. A new diagnostic test demonstrates good
clinical utility if it leads to fewer adverse reactions, improved
patient care, improved patient outcome, or equal outcome at
lower costs. A new radiographic procedure that provides the same
information as a palpatory procedure has poor utility and no diagnostic value because it provides the same information at a greater
cost and risk to the patient.
Outcome Assessment Procedures
The limited understanding of the nature, cause, pathophysiologic
condition, and diagnostic criteria for identifying JSDSs has stimulated a search for alternative and more valid outcome measures by
which to measure the effectiveness of chiropractic care. Escalating
health care costs and the need to document the appropriateness
and effectiveness of care further illustrate the need for the profession to develop and use valid outcome measures.295 Instead of
relying solely on procedures traditionally used to identify JSDS,
chiropractors should also use procedures that measure the effect
their treatment is having on the patient’s symptoms and function.
In this context, the name and nature of the disorder become less of
a focus, and more attention is paid to how the patient is functioning and responding to treatment.55,296,297
The disorders commonly treated by chiropractors are painful or have a significant effect on the patient’s ability to function.
Therefore, the degree of the patient’s pain and his or her ability
to perform physical maneuvers and activities of daily living are
important outcome measures of the efficiency and effectiveness
of chiropractic treatment. A number of the procedures presented
can be used in this context. However, many are more useful in
guiding decisions on where and how to adjust patients than they
are as outcome measures. Each examination procedure presented
includes a brief discussion on the procedure’s clinical usefulness
and appropriateness for use as outcome measures.
Symptoms of Joint Subluxation/
Dysfunction Syndrome
Pain is a common and clinically important sign of JSDS, but
JSDS cannot be excluded or confirmed by the presence or absence
of pain alone. Pain is considered a subjective finding and some
contend that subjective findings such as pain reproduction have
53
less significance than findings that are “objective.” However, many
so-called objective tests rely on the patient’s report of pain. For
example, the straight-leg raising test is considered an objective
test, yet it is the patient’s report of leg pain that constitutes a positive test. This is no different than applying pressure over osseous
or soft tissue structures and having the patient report the presence
or absence of pain. The use of provocative tests to localize a painful area is therefore a useful means for identifying musculoskeletal problems, including JSDS. These manual physical maneuvers
are designed to reproduce the patient’s symptoms or verify the
location of pain, thereby giving support for the local presence of
a dysfunctional process. Typically, these tests stretch, compress,
or distract specific anatomic structures with the patient reporting
pain characteristics. When patients experience pain caused by one
of these mechanical tests, there is likely to be a local mechanical
component contributing to the condition.
Joint dysfunction is typically, but not necessarily, symptomatic.
The nature and cause of joint pain and dysfunction cannot be determined from the pain pattern alone. Joint pain does not discriminate
between joint hypomobility, hypermobility, and clinical instability.
Furthermore, not all structures of the synovial joint are sensitive to
pain. Some are very poorly innervated, and some are not innervated
at all. The articular cartilage, nondisrupted nucleus pulposus, and
cartilaginous end plates are devoid of nociceptive innervation.131
Thus pathologic change within certain articular structures may be
insidious and well advanced before it becomes symptomatic.
Spinal or extremity joint pain is often poorly localized, and
sites of pain and pathologic conditions may not necessarily correspond. Disorders of the musculoskeletal system are often associated with areas of referred pain and hypalgesia.298,299
Referred pain is sclerogenic, ill-defined, deep, and achy. It is
referred from the deep somatic tissues of the involved joint to the
corresponding sclerotome. The anatomic sites of referred pain
correspond to tissues that share the same segmental innervation
(Figure 3-11).
Sites of referred pain may be more painful to palpation and of
greater intensity than the site of injury. The common phenomenon of interscapular pain with cervical joint derangement or disc
herniation illustrates this point. The body is also more adept at
discriminating sensations on the surface than pain originating in
deep somatic structures and joints.298,299 Ordinarily, the closer the
affected tissue is to surface of the body, the better the pain coincides to the site of injury.
Joint pain of mechanical origin characteristically has painfree intervals, whereas joint pain associated with inflammation is
more constant. Joint movement and the activities of daily living
often aggravate mechanical joint pain. Although it is often alleviated by deceased activity, total immobilization may accentuate
the pain response. Pain diagrams, visual and verbal analog scales
(Figure 3-12), and functional capacity questionnaires are very
helpful measures in the examination and quantification of painful
complaints.300-306
Because the character, location, quality, and intensity of pain
can vary greatly from individual to individual and from disorder
to disorder, it is essential to subject all painful joint disorders to a
thorough physical examination and to rule out contraindications
before considering adjustive therapy.
54
| Chiropractic Technique
C8
T2
C5
T3
T5
T4
T9
T10
T12
C7
T5
C8
T11
T12
L1
C8
L2
L4
C6
L2
C6
C8
L3
T1
T9
T10
T11
L1
T6
C6
C5
T5
T8
C6
T8
T3
T4
T4
T6
T7
T1
T1
T2
C8
C7
L3
S1&2
L5
L4
L5
S
1&2
L5
L4
S1&2
L5
A
C4
L2
L3
C5 L5
L4
C5
C7
C5
C6
L1
S1
S2 S1
C6
C7
L4
L5
L2
C8
L3
S1
L4
L4
Numbness
Pins/Needles
Scoring sheet for pain drawing
C7
C8
L4
C6
C7
C8
L5
L5
L4
S1
S2
S1
L5
S2
Anterior
Writing anywhere
Unphysiologic pain pattern
Unphysiologic sensory change
More than one type of pain
Both upper and lower areas of the body involved
Markings outside the body
Unspecified symbols
Score: 1 = Normal.
C7
B
Posterior
Anterior
Burning x x x x
Stabbing / / / /
Aching a a a a
L3
L3
C6

0 0 0 0
Posterior
Figure 3-11â•… Segmental areas of pain of deep somatic origin. A,
Interspinous ligament injection—Kellgren. B, Sclerotomal pain patterns.
(A from Lewis T: Pain, New York, 1942, Macmillan. B from Grieve
GP: Common vertebral joint problems, ed 2, Edinburgh, 1988, Churchill
Livingstone.)
Patient Observation
The examination of any regional complaint begins with superficial
observation and investigation for any signs of trauma or inflammation. These signs include abrasions, lacerations, scars, discoloration, bruises, erythema, pallor, swelling, or misalignment.
Acute injury, congenital or developmental defects, and many systemic diseases of the NMS are often represented by abnormalities
observed in posture or gait.
The human body uses an ingenious three-dimensional framework of bones, joints, muscles, and ligaments for posture and
movement.307 Therefore, the observational evaluation of NMS
1
1
1
1
1
1
1
5 or more = Functional overlay.
A
Visual analog pain severity scale
Instructions: Please make a mark on the line provided below
that corresponds to how you presently feel.
No
pain
Worst pain
imaginable
B
Figure 3-12â•… Tools to localize and record pain intensity. A, Pain dia-
gram. B, Visual analog scale. (A adapted from Mooney V, Robertson J:
Clin Orthop 115:149, 1976.)
function routinely incorporates an assessment of patient symmetry, posture, and locomotion. The examination is based on the
premise that there is a postural ideal that can be used as a comparative standard and that deviations in posture, gait, or movement
may identify NMS disease or dysfunction or predispose an individual to NMS disease or dysfunction. Poor posture can be viewed
as a faulty relationship of bones, ligaments, and muscles that produces an increased stress on the supporting structures leading to
decreased efficiency for maintaining the body’s balance over its
Chapter 3╅ Joint Assessment Principles and€Procedures |
base of support. Ample evidence supports the association of painful disorders of the NMS with restrictions to joint motion and
abnormalities in posture.308–321
Evidence also suggests that deviations from “ideal posture” may
predispose an individual to NMS dysfunction and possible joint
degeneration.199,322–326 However, the degree of deviation necessary
to affect a patient’s health has not been established. Individual biologic variation and adaptability certainly play a role in limiting the
development and morbidity of joint dysfunction and degenerative
joint disease. Those that would set a narrow standard for posture
and ROM ignore the research evidence that suggests a range of
normal individual variation.23,316,324,327–335
Gait Evaluation
Gait evaluation is conducted formally during the physical examination, but it begins as the patient walks into the examination
room. Locomotion involves integrated activity of numerous components of the motor system and therefore becomes an efficient
method for screening NMS function.
The objectives of gait analysis are to identify deviations, to
obtain information that may assist in determining the cause of the
deviations, and to provide a basis for the use of therapeutic procedures or supportive devices to improve the walking pattern.336
There are two basic phases of the normal pattern of gait: one
involves a weight-bearing period (stance phase) and the other, a
non–weight-bearing period (swing period) (Figure 3-13). Disease
or dysfunction may affect one phase and not the other, necessitating careful evaluation of both components.
Evaluation begins with a general impression of locomotion.
Is it guarded or painful? Is the patient protective of any part or
unwilling to put equal weight on each leg?
The movements of the upper and lower extremities are noted.
Length of stride, degree of pronation or supination, tilt of pelvis,
adaptational movements of the shoulder girdle, and pendulousness of the arms are assessed. Specific components of gait evaluation are listed in Box 3-4, and disorders that may alter gait are
listed in Box 3-5.
Apparent abnormal findings or deviations from the expected
pattern identified with gait analysis must be supported or validated by other test procedures, including muscle tests for strength,
length, tone, and texture, as well as tests for joint function.
BOX 3-4
Components of Gait Evaluation
Alignment and symmetry of the head, shoulders,
and trunk
Gross movements of the arms and legs, looking for
reciprocal and equal amplitude of movement
Symmetry of stride from side to side for length, timing, and
synchronization
Assessment of body vertical oscillations at an even
tempo
Assessment of pelvic transverse rotation, anteroposterior
rotation, lateral tilt, and lateral displacement through the
phases of gait
Assessment to determine if the lower extremities
medially rotate, then laterally rotate, going from swing to
stance
Assessment to determine if the knees have two alterations of
extension and flexion during a single-gait cycle
Assessment to determine if the ankles go from dorsiflexion
to plantar flexion when going from the stance phase to
the swing phase
Postural Evaluation
Like all physical examination skills, postural evaluation must
be learned and practiced. Reliable and accurate assessment is
founded on attention to proper technique. The room must
be appropriately lit to clearly illuminate the body parts being
examined and to prevent shadows from projecting false contours. The doctor should be oriented to the patient so that the
dominant eye is located in the midline between the landmarks
being compared.337 If observing the patient while he or she is
supine or prone, the doctor stands on the side of eye dominance
(Box 3-6).
When combining observation and palpation of asymmetry, it is
important that the doctor’s hands and eyes are on the same reference
plane. For example, when evaluating the relative heights of the iliac
crests, the doctor places a hand on each crest and positions the dominant eye in the midline on the same plane as his or her hands.
Figure 3-13â•… The phases of gait. A, Stance phase. B, Swing phase. (Modified from Adelaar RS: Am J Sports Med
14:497, 1986.)
55
56
| Chiropractic Technique
BOX 3-5
Disorders That May Induce Altered Gait
Pain or discomfort during the weight-bearing phase
Muscle weakness and imbalance
Limitation of joint motion—active, passive, or accessory
Incoordination of movement as a result of neurologic
condition (e.g., Parkinson syndrome)
Changes and deformities in bone or soft tissues
BOX 3-6
Determination of Dominant Eye
1. Bring both hands together to form a small circle with the
thumbs and index fingers.
2. Straighten both arms out, and with both eyes open, sight
through the small circle an object at the other end of the
room.
3. Close one eye. If the object is still seen, the open eye is
dominant. For example, if the right eye is closed and the
object is still seen, the left eye is dominant. If the right eye
is closed and the object is no longer seen, the right eye is
dominant.
The assessment of symmetry, locomotion, and posture is critical in the evaluation of NMS dysfunction. They are objective signs
supportive of NMS disease or injury310 and effective outcome measures for monitoring patient progress. Regional asymmetry should
trigger further evaluation of that area, but asymmetry alone does
not confirm or rule out the presence of segmental subluxation and
dysfunction syndromes.
Postural asymmetry is a challenge to homeostatic regulation
and does indicate potential areas of muscular imbalance, bony
asymmetry, and mechanical stress. Its relationship to initiating,
predisposing, or perpetuating segmental dysfunction should not
be overlooked. In a rush to find the specific level of spinal JSDS,
chiropractors often overlook significant postural decompensations that may predispose the patient to pain and dysfunction.
The patient with extremity or spinal complaints may not respond
to local therapy until gait and postural stresses are removed.
Spinal Postural Evaluation. Although deviations in spinal posture do not identify the presence or absence of a specific level of
spinal dysfunction, deviations do provide evidence of underlying
postural syndromes or the presence of painful NMS conditions.
Spinal postural assessment has demonstrated satisfactory reliability309,338-340 and validity as a screening procedure for distinguishing
symptomatic myofascial back pain subjects from normal subjects.310 In this capacity, it may function as a useful outcome measure to document changes in painful antalgic postures associated
with NMS disease and dysfunction.
During standing postural assessment, the patient is instructed to
assume a relaxed stance, looking straight ahead, with feet approximately 4 to 6 inches apart and arms hanging loose at the sides. The
patient should be in a gown or undergarments, and should not be
wearing shoes. If the patient has orthotics or corrective footwear,
posture is assessed with the patient’s shoes both off and on. The
evaluation is conducted from the posterior and anterior to determine distribution of weight and symmetry of landmarks in the
coronal plane and from the side to evaluate posture and landmarks
relative to the center of gravity line. In addition, the upper and
lower extremities are surveyed for deformity, pronation or supination, and internal or external rotation.
The examination should include a determination of the carriage of the center of gravity and symmetry of key bony and soft
tissue landmarks. Any curvatures, scoliosis, or rib humps should
be measured and recorded. The flexibility (Adams test) of the
curve should also be determined and noted.
The evaluation of spinal posture may be aided by the use
of a plumb line (Figure 3-14) and devices such as the posturometer, scoliometer, and bilateral weight scales. The plumb line
assessment from the posterior should find the gravity line, splitting the body into equal left and right halves. The plumb line
should pass from the external occipital protuberance through
the center of the spinal column to the center of the sacrum and
points equidistant from the knees and ankles. The lateral plumb
line assessment has the gravity line splitting the body into equal
front and back portions. The plumb line should pass from the
external auditory meatus down through the shoulder joint to the
greater trochanter of the femur, continuing down to just anterior to the midline of the knee and slightly anterior to the lateral
malleolus.
In a patient with suspected scoliosis, an assessment for potential leg length inequality and a screen for anatomic or functional
leg length discrepancy should be included. Suspected anatomic
discrepancy should be measured and radiographically confirmed
if clinically significant. Postural distortions with possible muscle
imbalance causes are identified in Table 3-2.
The identification of postural imbalances can be helpful in diagnosing disorders or in guiding clinical treatments. In some cases it may
be central to the identification of the underlying disorder, such as idiopathic scoliosis, and in others it can help guide treatment decisions,
such as exercise prescription in patients with postural imbalances and
LBP. Subsequent evaluations are used to monitor progress and make
decisions about treatment changes. The significance and usefulness
of these evaluations depend on repeatability sufficient to ensure that
ensuing changes are attributable to the prescribed treatment program
and not to any naturally occurring variability in posture. This may not
be attainable in all clinical situations; Dunk and coworkers341 demonstrated that the ability to return to the same starting posture exhibited
poor to moderate repeatability. This brings into question the benefit
and validity of using small deviations from ideal spinal posture in clinical decision making. Therefore, users of postural analysis tools should
interpret small to modest postural deviations from a vertical reference
with caution, because there are many inherent factors that can contribute to the variability of these measured postures.341 Studies have
also demonstrated that visual assessments for an increase or decrease in
�cervical or lumbar lordosis are not reliable or accurate.342,343
Leg Length Evaluation
The evaluation of leg length inequality incorporates consideration for both anatomic and functional discrepancies. Anatomic
inequality results primarily from osseous asymmetry. Functional
Chapter 3╅ Joint Assessment Principles and€Procedures |
TABLE 3-2
ommon Postural Findings With
C
Possible Muscular Imbalances
A-P or P-A Postural
Examination
Head tilt
Neck extensors and/or
scalenes
SCM
Trapezius (upper,
lower) latissimus
Serratus anterior
Rhomboids
Subscapularis, teres
minor, infraspinatus
TFL, adductors,
psoas, quadratus
lumborum, gluteals
TFL, sartorius, gracilis
Hamstrings, tibialis
anterior, peroneus,
piriformis, psoas
Head rotation/tilt
Shoulder tilt
Scapular winging
Scapular heights
Arm rotation
Pelvic unleveling
Genu valgus/varus
Leg rotation
Lateral Postural
Examination
Forward head carriage
Neck extensors, longus
coli, scalenes
Trapezius (middle and
lower)
Psoas
Quadriceps, hamstrings,
sartorius, gracilis,
abdominals, gluteus
maximus
Gastrocnemius, soleus
Quadriceps, popliteus,
gastrocnemius, soleus
Thoracic kyphosis
Lumbar lordosis
Pelvic tilt
Figure 3-14â•… Anteroposterior and lateral plumb line evaluation of
�
spinal
posture.
Lateral View
The gravitational line should pass:
Through the earlobe
Just anterior to the shoulder joint
Through the midline of the thorax
Through the center of L3
�vertebral body
Through the greater trochanter
Just anterior to the midline of
the knee joint
Just anterior to the lateral
malleolus
Posterior or Anterior View
The gravitational line should pass:
Through the midline of the
skull
Through the spinous processes
Through the gluteal crease
Midway between the knees
Midway between the ankles
The following landmarks should
be evaluated for unleveling or
asymmetry:
Gluteal folds
Gluteal contours
Iliac crests
Posterior superior iliac spine
Rib cage
Inferior angles of the scapula
Vertebral borders of the
scapula
Acromioclavicular joints
Earlobes
leg length inequality implies that the legs are anatomically of equal
length but appear unequal as a result of a disorder in the NMS
system. Anatomic asymmetry is viewed as a potential source of
derangement and dysfunction that is potentially treatable with
heel or sole lifts. Functional asymmetry is viewed primarily as a
consequence of dysfunction.
57
Forward lean
Knee hyperextension
A-P, Anterior-to-posterior; P-A, posterior-to-anterior; SCM, sternocleidomastoid; TFL,
tensor fascia lata.
Leg length evaluation has a long history of affiliation with chiropractic, and functional leg length inequality is considered an
important sign of spinal or pelvic subluxation/dysfunction syndromes.344 Spinal joint dysfunction is hypothesized to potentially
affect leg length by inducing reflex alterations in spinal muscle
balance and unleveling of the pelvis and legs.344-346
Disturbances in sacroiliac function and pelvic alignment are
theorized to induce torsion between the innominates and affect
leg length by creating positional changes in the femoral heads
or imbalances in hip flexor and extensor muscle tone.344 A significant percentage of practicing chiropractors and a number of
system technique methods emphasize the role of leg length evaluation in detecting spinal subluxations/dysfunction and directing decisions on where, when, and how to adjust patients.345-347
Leg alignment change in response to provocative springing
(vertebral challenge) is used by some chiropractic techniques to
determine the level of spinal dysfunction and direction of therapeutic adjustive thrust.346
58
| Chiropractic Technique
Leg length equality can be assessed by physical means or by
radiographic evaluation. Evaluation of inequality by physical
means includes procedures that assess leg length through direct
tape measurement, by visual inspection, or indirectly through
combined visual and palpatory assessment of symmetry. Physical
measures are appropriately used to screen for leg length inequality,
estimate the amount of any noted discrepancy, and participate in
differentiating anatomic leg length inequality from functional leg
length inequality. Physical assessment procedures cannot determine exact differences in anatomic length.
X-ray evaluation is necessary when precise determination of leg
length is required. Radiographic procedures should not be used
to screen for possible leg length inequality. X-ray evaluation of leg
length should be considered only after suspicion of a significant
anatomic leg discrepancy is identified and corrective heel or shoe
lifts are being contemplated. Radiographic procedures include
both standing and supine methods. Radiographic evaluations are
recognized as reliable and valid procedures for determining anatomic leg length discrepancies.345
Standing methods are used to assess the comparative height of
the femoral heads and include full spine, lumbar, and femoral head
views. Femoral head views afford the most accurate evaluation of
femoral head height because they eliminate the false appearance
of inequality that can result from rotation of the patient’s pelvis
during patient positioning. When precise comparison of length is
desired, supine methods are usually used. Of these, the scanogram
is the method most commonly used.
The most common physical assessment method used in chiropractic practice combines visual assessment and palpation of
�
symmetric
bony landmarks. Evaluation is performed with the
patient in a prone or supine position, with his or her shoes on or
off, and the doctor standing at the end of the table. The doctor
evaluates equality by contacting and comparing the inferior poles
of the medial malleoli, the soles of the shoe, or the patient’s heels
(Figure 3-15). It is advisable to remove the shoes if significant
shoe wear is present or if the doctor suspects that the patient’s heel
and shoe cannot remain in firm contact. When using the soles of
the shoe or the patient’s heels as the comparative landmark, it is
important for the doctor to neutralize the ankles to prevent eversion or inversion from creating a false appearance of inequality.
If leg length inequality is noted in the prone position, the
doctor bends the patient’s legs to 90 degrees and again observes
for inequality. If the inequality remains anatomic, shortening
of one tibia is considered. If the heels approach or reach equal
height, some degree of functional leg length inequality is suspected. Various interpretations of this process (leg checks) have
been developed and are in common use. The Derifield pelvic leg
check is foremost in this regard and is commonly affiliated with
the Activator and Thompson technique systems.348,349 The specifics of this test are presented in Chapter 5 in the section covering
pelvic evaluation procedures.
Despite the common use of physical procedures to detect leg
length inequality, significant questions concerning the clinical
significance and reliability, validity, and responsiveness of these
methods remain.265,344,345,347,350 Procedures using tape measurement, iliac crest comparative height checks, or visual leg checks
to assess comparative leg length have demonstrated mixed
results.345 These procedures have demonstrated both poor and
Figure 3-15â•… Prone evaluation of leg length. A, Evaluation for symmetry of leg length by comparing the patient’s heels or inferior poles of the malleoli. B, Evaluation of tibial length by comparing heel symmetry in a flexed-knee position.
Chapter 3╅ Joint Assessment Principles and€Procedures |
good interexaminer reliability.346,347,351-357 A significant number of the studies using visual leg checks have been criticized
for poor experimental design or statistical analysis.265,344,345 Leg
length inequality testing has also failed to respond as predicted
to thoracic rotary vertebral challenge and thoracic adjustment.346,358 Schneider and associates246 performed an interexaminer reliability evaluation of the prone leg length analysis
procedure and found good reliability in determining the side
of the short leg in the prone position with knees extended, but
found poor reliability when determining the precise amount
of that leg length difference. In addition, they found that the
head rotation test for assessing changes in leg length was unreliable in this sample of patients, nor did there appear to be any
correlation between the side of pain noted by the patient and
the side of the short leg. It was interesting to note that all 45
patients in this sample were found by both clinicians to have
a short leg.246 The weakest element in the leg check procedure
is the second position, with the knees bent to 90 degrees, in
which overall agreement is poor, reaching only as high as “fair”
25% of the time.345,356
The validity of visual leg checks for anatomic accuracy or subluxation and dysfunction detection has yet to be evaluated clinically.
Cooperstein and colleagues did determine that visual leg checks
were accurate in measuring artificially induced leg length inequality,357 but no studies have been done to measure their relationship
to level of spinal dysfunction or treatment outcomes. Because of
the lack of validity testing, it is difficult to form any definitive
conclusions as to the clinical utility of these procedures.345
Range-of-Motion Assessment
Measurement of joint mobility is a critical element in the
evaluation of NMS function, and qualitative and quantitative evaluation of joint motion is a fundamental component
of the examination of the NMS system. Significant limitation
and asymmetry of movement is considered to be evidence of
NMS impairment,359 and improvement in regional mobility
may be a valuable outcome measure for assessing effectiveness
of treatment.
Disorders capable of altering individual joint and regional
spinal movements are extensive. They include joint subluxation/
dysfunction, dislocation, effusion, joint mice, myofibrosis, periarticular fibrosis, muscle hypertrophy, degenerative joint disease,
muscle guarding, and fracture. Other nontraumatic disease states
with pathologic effects on somatic structures or the nervous
�system also produce abnormalities in movement.
Although regional ROM assessment has demonstrated the
ability to differentiate individuals with low back disorders from
those without,310,360 spinal abnormalities in GROM are more valuable in identifying and monitoring NMS dysfunction than confirming a specific level of joint subluxation/dysfunction. Regional
abnormalities in range of spinal motion are potential signs of
dysfunction, but they do not confirm the presence of segmental
joint dysfunction. GROM may be falsely positive in situations in
which spinal injuries or disease affects the nonsegmental somatic
tissues and spares the vertebral joints. In these circumstances,
altered regional movements are present, but the loss of mobility is
59
uniform, and the individual spinal motion segments demonstrate
normal JP and EP (feel). Conversely, normal regional ROM may
be falsely negative in circumstances in which individual spinal
joint restrictions are concealed by compensatory hypermobility
at adjacent joints.
Evaluation of repeated regional spinal movements in conjunction with the patient’s description of pain and limitations to
movement have been promoted as effective tools for diagnostically classifying back pain patients.361,362 The information gained
about the patient’s symptomatic and mechanical responses to
loading allows the clinician to determine which specific movements, positions, and activities to either pursue or avoid in the
treatment plan.
The McKenzie method of evaluation and treatment is the
most widely practiced procedure using repeat movements to classify back pain patients. It is common for chiropractors to use
McKenzie diagnostic procedures, but is more commonly used by
physical therapists. Donelson, Aprill, and Grant362 demonstrated
that the procedures were capable of reliably differentiating discogenic from nondiscogenic pain and a competent from an incompetent annulus. In comparison with MRI, it also demonstrated
superior ability in distinguishing painful from nonpainful discs.362
In a later commentary article, Delany and Hubka363 re-evaluated
the data from the original study and concluded that the study
demonstrated “informative but not definitive” ability to detect
discogenic pain. They concluded that “high sensitivity but low to
moderate specificity was demonstrated.”
Early reliability testing of McKenzie procedures demonstrated mixed results. 364,365 However, recent studies have
concluded that the McKenzie method demonstrates good reliability for classifying patients into syndrome categories based
on repeated movements and the principle of centralization of
pain.366-368
Measurement Procedures
Methods for assessing mobility are commonly used and include
both visual and instrument-based procedures. They range from
goniometric and inclinometric measurements to the more technical approaches of computerized digitation.308,369 Visual observation and the fingertip-to-floor method of recording motion
have demonstrated mixed reliability370 and are considered to be
invalid tests because they cannot effectively differentiate lumbar mobility from hip or thoracic movement. The modified
Schober method of measuring lumbar mobility has shown consistent reliability, but it has limited use because it measures only
lumbar flexion.370-372
The use of inclinometers for spinal ROM and inclinometers or goniometers for extremity ROM is becoming a minimal
standard.359 For the spine, the one- or two-inclinometer method
as described by Mayer and associates308 is a reliable, inexpensive,
and efficient technique. With the exception of one study,373
evaluation of motion with hand-held inclinometric measuring devices has demonstrated consistent reproducibility within
and between examiners.308,370,371,372-376 It can be used in the
�measurement of all spinal movements, including trunk rotation,
when the spine is in a flexed position (Figures 3-16 and 3-17).
However, the range of trunk rotation is �significantly �limited
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| Chiropractic Technique
Figure 3-16â•… Measurement of lumbar range of motion using dual inclinometers. A, neutral starting position for evaluating flexion and extension;
B, measurement of extension; C, measurement of flexion; D, measurement of left lateral flexion. (Evans, RC: Illustrated orthopedic physical assessment,
ed 3, Mosby, Elsevier, St. Louis, Mo 2009.)
when it is placed in a flexed position. In the spine, quantitative measures of joint mobility rely primarily on regional ROM
measures as a result of joint inaccessibility and limited ROM.
Methods for estimating the quality and quantity of individual
spinal motion through manual palpation have been developed
and are covered regionally in Chapter 5.
Evaluation of spinal and extremity mobility must take into
consideration the normal variations that exist between individuals
and gender. Alterations in mobility may be a product of occupation, recreation, or aging, and may not be associated with dysfunction or pain. This increases the importance of making a bilateral
comparison of joint and spinal mobility.
Spinal and extremity joint motion are measured in degrees relative to the zero or starting position. In a patient demonstrating
50€degrees of cervical extension and 55 degrees of cervical �flexion,
the motion is recorded as “EXT/FL 50-0-55.” All physiologic
movements, on both sides of the zero position (0 degrees), should
be measured and recorded. Table 3-3 outlines the common format
for recording spinal and extremity ROM.
Palpation
Palpation is the application of variable manual pressures, through
the surface of the body, to determine tenderness, shape, size, consistency, position, and inherent motility of the tissues beneath.61 It can
also serve as an important doctor-patient communication tool, helping patients understand the significance of their �problems because
they can feel the provoked pain and resistance as they are palpated.240
Furthermore, palpation is the oldest examination technique used by
chiropractors to detect subluxation/dysfunction.74,234-237
Chapter 3╅ Joint Assessment Principles and€Procedures |
61
B
C
D
Figure 3-17â•… Measurement of cervical ranges of motion using dual inclinometers. A, measurement of extension; B, measurement of right lateral
flexion; C, neutral starting position for measuring rotation; D, measurement of right rotation. (Evans RC: Illustrated orthopedic physical assessment, ed 3,
Mosby, Elsevier, St. Louis, Mo 2009.)
Like observational skills, palpation skills are learned tasks that
take hours of devotion and practice. Good palpation skills are the
result of both physical abilities and mental concentration. The
skillful palpator is one who has developed an improved ability to
tactually discriminate and mentally focus.
Palpatory procedures are commonly divided into static and
motion components. Static palpation, which is often further
subdivided into bony and soft tissue palpation, is performed
with the patient in a stationary position. Motion palpation is
performed during active or passive joint movement and also
involves the evaluation of accessory joint movements. Motion
palpation procedures have been an integral part of chiropractic since its inception, but not until the work and cultivation of
Gillet41-45 and Faye52,53 have formalized techniques been widely
disseminated.
Reliability of Palpation Procedures
Clinical evaluation of palpation procedures has increased significantly in the last several decades. The majority of tests have
been conducted on reliability. Reliability testing for the various
manual palpation procedures has demonstrated mixed results.
Interexaminer palpation for bony alignment and muscle tension has demonstrated poor results, but palpation for bony and
soft tissue tenderness has established good to excellent interexaminer reliability.245,255,377-386 Palpation for bony and soft tissue
tenderness is frequently cited as one of the most valuable clinical
cues for identifying dysfunction and targeting spinal manipulation. Research by Schneider and coworkers386 confirmed the reliability of pain provocation. They tested the reliability of spinal
palpation for segmental mobility testing and pain provocation
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| Chiropractic Technique
TABLE 3-3
Assessment of Spinal and Extremity
Motion
Spinal Motion
Extension
Right lateral
bending
Right rotation
0
0
0
Flexion
Left lateral
bending
Left rotation
0
0
0
0
0
0
Flexion
Adduction
Internal rotation
Pronation
Ulnar deviation
Eversion
Extremity Motion
Extension
Abduction
External rotation
Supination
Radial deviation
Inversion
in 39€patients with a history of LBP. The �resulting kappa values
showed generally good reliability for the springing palpation that
relied on patient self-reports of pain but poor reliability for assessment of mobility.386
Joint motion palpation, particularly passive EP assessment, is
recognized as an essential skill by manual medicine disciplines387
and is used extensively by chiropractors, physical therapists, osteopaths, and medical manipulators in clinical practice as an indicator for spinal manipulation and mobilization. However, despite a
few noteworthy exceptions that identified good interexaminer and
intraexaminer reliability,384,385,388-391 the majority of studies evaluating spinal and sacroiliac joint (SIJ) mobility tests have identified
poor interexaminer reliability and good intraexaminer reliability.*
Some studies have shown weak or clinically insignificant reliability of motion palpation for certain groups of young, asymptomatic subjects.407-410 Most other studies have obtained poor to mixed
results,247,378,391 with a few demonstrating an acceptable level of
reliability for motion palpation testing.392,398 A summary of reliability studies conducted by Haneline and Cooperstein for motion
palpation, pain provocation, landmark location, and alignment is
presented in Appendix 2.
Good intraexaminer reliability in the face of poor interexaminer reliability should be viewed with caution. Good intraexaminer
reliability does allow the examiner to evaluate how a test responds
to treatment and may be helpful in directing individual patient
treatments, but the ability to show internal consistency has limited value if different examiners cannot agree on their findings.271
The poor interexaminer reliability demonstrated in the majority of studies evaluating motion palpation is likely the product of
several factors. One may be the very small qualitative and quantitative changes it attempts to measure. The line between normal
and abnormal segmental joint movement has not been clearly
established.411 In this environment, each examiner develops his
or her own standard of what constitutes �pathologic movement.
Each examiner must develop his or her own “feel” for what is
*References 253, 268, 269, 369, 378, 380, 383, 385, 391-406
abnormal, with no common basis for comparison. The wide range
of techniques taught and individual modifications and idiosyncrasies that each practitioner develops further complicate reliability. Interexaminer reliability is also likely negatively affected by
the inability of examiners to precisely or repeatedly identify spinal bony landmarks and segmental joint level of palpation.391,412
Interexaminer reliability for motion palpation may demonstrate
poor results not because examiners are inaccurate at sensing movement changes but because they are mislabeling and disagreeing
on the joints that each is palpating. Furthermore, there is growing evidence that the biomechanical effects of spinal manipulation
may not be as joint-specific as previously thought,413,414 and if the
biomechanical effects are more widespread, we may be focusing on
the wrong clinical question. A more appropriate clinical research
topic might be the reliability of motion palpation assessment
within a spinal region or two or three spinal motion segments.
The question of whether a multidimensional diagnostic approach
to the physical examination of mechanical spine pain might lead
to more reliable outcomes has had limited investigation. A study
designed to assess the intraexaminer and interexaminer reliability of
such an approach demonstrated moderate levels of intraexaminer
reliability for the decision to manipulate a certain spinal segmental level and fair interexaminer agreement pooled across all spinal
joints. However, the conclusion of the study was that the common diagnostic methods, including visual postural analysis, pain
description by the patient, plain static erect x-ray film of the lumbar
spine, leg length discrepancy, neurologic tests, motion palpation,
static palpation, and orthopedic tests used on patients with chronic
mechanical LBP are not reproducible. They further suggest that the
implementation of these examination techniques alone cannot provide reliable information concerning where to direct a manipulative
procedure in patients with chronic mechanical LBP.291
Based on available information, it seems reasonable to conclude the following: Palpation for bony and soft tissue pain and
movement-induced joint pain (joint provocation or �challenge)
are reliable spinal manual examination procedures. Intraexaminer
reliability for spinal motion palpation is mixed and interexaminer
reliability for spinal motion palpation is generally poor. It is difficult to evaluate the interexaminer reliability of motion palpation
because of inherent difficulties related to the standardization of
the procedure, the inherent problems with identifying a specific
segmental level of palpation, and the subtlety of functional spinal
joint lesions. The following list provides a more detailed summary
of the present status of spinal palpation reliability:
1. Interexaminer reliability for segmental ROM palpation and
EP (end feel) is generally poor.
2. Interexaminer and intraexaminer reliability for EP evaluation is slightly better than segmental ROM palpation.
3. Intraexaminer reliability for EP motion palpation is good.
4. Interexaminer and intraexaminer reliability for joint pain
provocation (challenge) tests is fair to good.
5. Interexaminer and intraexaminer reliability for palpation of
bony or soft tissue pain is good.
6. Interexaminer and intraexaminer reliability for palpation
for soft tissue textural changes is poor.
7. Interexaminer and intraexaminer reliability for regional
ROM is good.
Chapter 3╅ Joint Assessment Principles and€Procedures |
8. Interexaminer and intraexaminer reliability for leg length
evaluation is good for the prone, extended knee position
and poor (less than chance agreement) in the prone flexed
knee position.
If intercollege standards for identification of abnormal spinal segmental motion can be developed, and agreement reached on the
degree of joint specificity that is needed, spinal motion palpation
may have the potential to develop improved interexaminer reliability. Insight into how this may be educationally accomplished is
illustrated by an experiment conducted by Harvey and Byfield.415
They constructed a mechanical spinal model that was covered with
leather to simulate skin and equipped with devices for artificially
fixating segmental motion. Good interexaminer agreement was
demonstrated by 8 graduate chiropractors and 19 final-year chiropractic students when given a choice between movement and the
absence of movement. If mechanical models can economically be
designed to simulate varying degrees of reduced movement, rather
than complete absence of movement, they might have a valuable
role to play in teaching and improving palpation reliability.
Validity of Palpation Procedures
Although the reliability of spinal motion palpation procedures has
been extensively evaluated, there is a limited body of literature
on the validity of motion palpation. A summary of validity studies is in Appendix 3. One of the early promising validity studies
on spinal joint assessment was conducted by Jull, Bogduk, and
Marsland.290 They investigated the accuracy of manual examination procedures in locating painful cervical joints confirmed by
diagnostic nerve blocks. Using a combination of pain response
and accessory and physiologic joint movements, a group of therapists identified the appropriate individuals and levels of abnormal painful cervical joints with 100% sensitivity and specificity.
In another study,416 physiotherapists were able to identify 24 of 26
painful vertebral levels that correlated to a single level of unilateral
multifidus muscle wasting confirmed by ultrasound examination.
The examination consisted of segmental motion palpation methods with an evaluation for pain reproduction and abnormal resistance to movement.
Although these results are quite dramatic, the results are somewhat suspect. The procedures used during injections did not
control for placebo effects and possible false-positive responses.
The possibility of false-positive responses bring into question
the accuracy of using uncontrolled injections as a gold-standard
comparison.417 Furthermore, both studies included evaluations
of mobility and pain. This makes it impossible to discern which
procedure or combination of procedures is responsible for identifying the painful joint. Some have suggested that it is the provocation of pain and the patient’s verbal pain cues that are responsible
for identifying symptomatic spinal joint dysfunction.394,418
In a subsequent single-blind study, Jull, Treleaven, and
Versace419 were able to demonstrate that “cervical symptomatic joint dysfunction could be identified without reference to
specific vertebral reports of pain by the subject.” The study did
not rely solely on the evaluation of abnormal motion, but also
allowed the examiner to determine the level of symptomatic joint
dysfunction by the presence of “tissue stiffness and associated muscle reactivity or increased resistance through range of motion.” The
63
authors concluded that “mechanical variables in segmental tissue
stiffness, which are related to symptoms, can be detected.”419
King and associates258 replicated the study of Jull and colleagues257 with placebo-controlled facet blocks to determine the
sensitivity, specificity, and likelihood ratio of manual examination
for the diagnosis of cervical zygapophyseal joint pain. Manual joint
motion examination demonstrated high sensitivity for cervical
zygapophyseal palpated joint pain at the segmental levels that were
commonly symptomatic, but its specificity was poor. Likelihood
ratios were barely greater than 1:0, indicating that manual palpation for joint pain lacked validity. However, the study did have
some significant methodologic limitations that affect its value.
The manual examinations were not conducted by chiropractors
and were performed by only one examiner with limited manual
examination training. The reference standards (facet blocks) were
applied only to subjects with positive manual examination findings and not those who had negative findings.
Humphreys and coworkers420 studied the validity of motion
palpation using the presence of a congenital block vertebra as a
gold standard. Twenty fourth-year chiropractic students had to
identify the hypomobile segments in three subjects with a congenital block vertebra. They found a sensitivity of 74% and a specificity of 98% for the general detection of all blocks and a kappa value
of 0.67, which is considered good. Assuming that block vertebra
are a fair representation of marked spinal joint hypomobility, they
concluded that their substantial demonstrated agreement lends
support to the validity of motion palpation in detecting major
spinal fixations in the cervical spine.
A study evaluating the prevalence of positive motion-�palpation
findings (so-called fixations and spontaneous pain response) in relation to self-reported LBP status was performed to determine the
sensitivity and specificity of the motion-palpation technique on the
sacroiliac and lumbar joints.421 No logical pattern of fixations and
spontaneous pain reactions were found in relation to the LBP status
of the patients. The sensitivity was low for fixations and pain, but the
specificity was significantly higher for pain in the mid-lumbar area.
However, there was no strong association found between fixations
and the examiners’ interpretation of a pain reaction in response to
motion palpation, leading to the conclusion that motion palpation
does not appear to be a good method to differentiate persons with
or without LBP.421 However, it was concluded that it was possible to
dissociate the findings of fixations and those of pain reactions.421
The identification of hypomobility with prone P-A mobility
testing has demonstrated validity in identifying patients who are
more likely to benefit from manipulative therapy.260,261 This procedure was combined with pain of less than 16 days’ duration, no
radiating pain below the knee and low fear avoidance belief scores
as criteria to select patients for a short trial of manipulative therapy. Subsequent evaluations have indicated that the other criteria
may be more predictive of outcome and that the P-A mobility
testing may not add significant value.
Another validity study using dynamic x-ray as a reference standard compared lower cervical lateral glide motion palpation to lateral flexion radiographs in patients presenting with mechanical
neck pain.422 The lateral gliding test for the cervical spine was as
good as the radiologic assessment for the diagnosis of intervertebral
joint dysfunction in the lower cervical spine in this small group of
64
| Chiropractic Technique
patients. These results indicate that the lateral gliding test for the
cervical spine is as accurate as lateral flexion radiographs in identifying restricted intervertebral mobility in the lower cervical spine.422
However, lateral flexion radiographs have not been validated as a
reliable and valid tool for identifying cervical dysfunction.
The clinical value of diagnostic procedures can also be assessed
relative to their ability to change in response to treatment.
Investigations into the responsiveness of motion palpation to adjustive treatments are limited to one randomized, controlled study
conducted on thoracic rotational adjustments.291 Patients were evaluated for thoracic rotational EP restrictions and �randomly assigned
to treatment and control groups. When re-examined by the blinded
evaluators, those patients receiving treatments did show significant
postmanipulative reductions in EP restrictions. Segmental EP palpation was thus found to have “utility as a postmanipulative evaluative test for patients who are symptomatic or mildly symptomatic
in the thoracic spine.”293 This provides encouraging evidence that
chiropractors may be able to manually palpate postmanipulative
segmental EP restriction changes in human subjects.
The question also arises as to whether or not reliability and
validity of motion palpation may be demonstrating less than optimal results because chiropractors are asking the wrong questions
and not structuring the experiments accordingly. The majority of
procedures evaluated to date have been based on the premise that
a precise level of spinal dysfunction needs to be ascertained before
effective treatment can be rendered. Hass and Panzer271 question
if this is an accurate assumption. They wonder if specific localization “might not be necessary for correction of the ‘true’ underlying manipulable subluxation syndrome.” They pose the possibility
that identification of regional dysfunction might be sufficient for
effective treatment of dysfunction.
As discussed previously, if identification of regional dysfunction were sufficient to establish effective treatment, it would likely
be more reliable than procedures used to identify a specific level
of dysfunction.271 Although this may be a valid point, Hass and
Panzer271 correctly point out that it needs to be examined. It would
be premature to abandon the specificity model without an established alternative “biomechanical model or clinical evidence to
suggest how big the zone of agreement might be or how it might
vary in different regions.”271
To address this issue, Hass and associates423 conducted a preliminary investigation to evaluate the efficacy of a specific diagnostic
indicator (segmental EP) to see if it improved spinal manipulative
outcome. The study evaluated patients with neck pain who were
randomized to receive cervical spine manipulation at restricted levels identified by motion palpation versus manipulation at levels randomly generated by a computer. The results show that both groups
had similar, and in some cases dramatic, improvements in symptoms
directly after receiving one HVLA cervical adjustment. The results of
this study indicate that cervical EP-directed manipulation does not
improve same-day outcomes in pain or stiffness. The outcome lends
support to the hypothesis that spinal �manipulation may have a more
generalized, nonspecific mechanism of action in relieving symptoms.
It also implies that the mechanical effects associated with manipulation may lack spatial specificity and specificity of adjustive contacts
and adjustive vector may not be as important as generally thought.
Although the evidence from this study indicates that using EP
to identify the level of dysfunction does not improve the measured
outcome, it would be inappropriate to draw conclusions from this
study alone. It is the only study to clinically investigate this topic
and it has a number of limitations that significantly affect its clinical
implications. First, it measures the effects of only one adjustment
on immediate and same-day pain and stiffness reduction. It is likely
that manipulation has a dose-dependent therapeutic effect,424 and
this trial does not come close to approximating the typical course of
adjustive treatments. Adjustive treatments for a cervical mechanical
pain syndrome average 6 to 12 treatments over the course of a few
weeks. EP assessment also may not be a valid indicator for same-day
postmanipulative pain and yet valid in directing therapy that has
an effect on other clinical outcomes such as pain and function over
time. The immediate pain and stiffness relief noted by both groups
may also be attributable to placebo or nonspecific effects associated with assessment and treatment, concealing differences between
groups that might have developed over time.
Despite the controversy surrounding motion palpation techniques and a call to abandon motion palpation techniques,425 the
majority of chiropractors and other manipulating professions continue to use these procedures and consider them to be reliable and
valuable methods.74,283,292,387 Although chiropractors may not be as
informed and questioning of motion palpation procedures as they
should be, it is clear that the evaluation of motion palpation procedures is incomplete. Although evidence is building that spinal
intersegmental ROM palpation has poor interexaminer reliability,
evidence does imply that it may have clinical value in context with
other manual examination procedures, especially when incorporated with pain provocation. The results concerning the segmental
motion palpation tools are mixed and, in a number of cases, are
inconclusive. It is premature to discard a safe, low-cost, and potentially useful procedure. There is not enough evidence to draw firm
conclusions on the validity of a number of manual examination
procedures at this time. Further research into various palpatory regimens is necessary to evaluate and differentiate clinically relevant and
useful palpation procedures. Within this context, it is important to
remain informed and not rely excessively on any one procedure, but
to use a combination of diagnostic procedures and allow the weight
of evidence to build a clinical impression of the patient’s problem.
It is also important to stress that all clinical procedures have
imperfect diagnostic reliability and validity. Saal426 reviewed the
literature on invasive spinal diagnostic tests (imaging studies, facet
joint diagnostic blockade, anesthetic blocks, lumbar discography,
NR blockade, sciatic nerve block, posterior ramus block, and subcutaneous injection) and concluded that there are inherent limitations in the accuracy of the diagnostic tests they evaluated. Although
the reliability of all palpatory procedures is not at the same level as
the reading of a thermometer or the taking of blood pressure (sphygmomanometry), it is comparable to cardiac auscultation.427 The
agreement between observers and the phonocardiographic gold
standard in the correct identification of S4 and S3 heart sounds was
poor and the lack of agreement did not appear to be a function of
the experience of the observers. The overall interobserver agreement for the detection of either S4 or S3 was little better than chance
alone.427 Yet cardiac auscultation continues to be taught and used
because of the low-risk clinical information it yields. The key is for
each clinician to understand the strengths and limitations of the
procedures they may use. Clinical decisions concerning the application and interpretation of diagnostic and therapeutic �procedures
Chapter 3╅ Joint Assessment Principles and€Procedures |
should be based on the best available evidence. For each procedure
it is important to understand its comparative advantages, limitations, and costs. When available, knowing a diagnostic test’s specificity, sensitivity, predictive value, and likelihood ratios can only
lead to better risk-benefit assessments.
Sacroiliac Articulation
A separate and focused discussion of the SIJ is warranted based on the
many specialized manual examination procedures that have been developed to evaluate its function.428 Dysfunction of the SIJ is defined as a
state of relative hypomobility associated with possible altered positional
relationships between the sacrum and the ilium.429,430 Motion palpation and pain provocation tests have been used in various forms and
advocated by a number of professions employing manual therapies in
the assessment and treatment of SIJ dysfunction.431-435 However, the
results of the reliability studies for mobility tests and pain provocation
tests of the SIJ have been mixed. Laslett and Williams436 reported in
1994 that pain-provocation SIJ tests are reliable if performed in a highly
standardized manner, using sufficient force to stress the SIJ. The results
of a review of SIJ tests by van der Wurff and associates437 could not
demonstrate reliable outcomes and concluded that there is no evidence
on which to base acceptance of mobility tests of the SIJ into daily clinical practice. Hungerford and coworkers438 demonstrated that an altered
pattern of intrapelvic motion could be reliably palpated and recognized
during the Stork test (a modified interpretation of the Gillet test), and
that the practitioner could distinguish between no relative movement
and anterior rotation of the innominate during a load-bearing task.438
Tests designed to provoke a patient’s pain appear to have more
support for use in identifying patients who may have SIJ region
dysfunction than do tests presumed to measure SIJ alignment or
movement.439 Provocation SIJ tests are more frequently positive in
back pain patients than the accepted prevalence of SIJ pain.440 This
indicates that individual tests may be confounded by a number
of false-positive responses. Laslett and colleagues441 tested provocation tests and found that any two of four positive tests (distraction,
compression, thigh thrust, or sacral thrust) or three or more of the
full set (distraction, compression, thigh thrust, sacral thrust, and
Gaenslen sign) were the best predictors of reducing or abolishing a
patient’s pain by intra-articular SIJ anesthetic injection. They further concluded that when all of the SIJ provocation tests are negative, painful SIJ pathologic conditions may be ruled out, suggesting
that provocation SIJ tests have significant diagnostic utility.
Arab and coworkers442 evaluated intraexaminer and interexaminer reliability of individual motion tests and pain provocation tests
for the SIJ and found both to have fair to substantial reliability.
They also looked at “clusters” of motion palpation or provocation
tests and found moderate to excellent reliability. Intraexaminer
and interexaminer reliability of composites of motion palpation
and provocation tests were also considered substantial to excellent.
They therefore concluded that composites of motion palpation
and provocation tests together have reliability sufficiently high for
use in clinical assessment of the SIJ.442
Manipulative treatment methods for the SIJ are based explicitly or
implicitly on the presumption that some biomechanical dysfunction
causes the SIJ or its associated soft tissues to become painful. This
hypothesis may be questioned because the means for identifying dysfunction are based on an evidential base with �disputed or conflicting
results concerning reliability and validity of SIJ dysfunction tests.443
65
Bony Palpation
The major goal of bony palpation is to locate bony landmarks
and assess bony contour for any joint malpositions, anomalies, or
tenderness. Typically, the palmar surfaces of the fingers or thumbs
are used because they are richly endowed with sensory receptors.
Light pressure is used for superficial structures, gently increasing
pressure for deeper landmarks.
During spinal palpation, the pelvis, lumbar, and thoracic
regions are customarily evaluated while the patient is in the prone
position and the patient’s cervical spine is evaluated in the sitting
or supine position. The spinous processes in the entire spine—the
articular pillars in the cervical spine, the transverse processes in
the thoracic spine, and the mammillary processes in the lumbar
spine—are palpated for tenderness and compared for contour and
alignment (Figure 3-18). The cervical articular pillars and thoracic
Spinous process
alignment
Spinous process
alignment
Interspinous space
palpation
Mammillary process
alignment
Transverse process
alignment
Figure 3-18â•… Palpation for bony tenderness and alignment of segmental
spinal landmarks.
66
| Chiropractic Technique
transverse process are both palpated through overlying muscular
layers, and tenderness in these structures must be differentiated
from tenderness in overlying soft tissues. The lumbar mammillary
processes are not directly palpable in most individuals. They are
located by a sense of deep resistance palpated through the overlying muscular layer. Individual motion segments are often located
relative to these bony landmarks, and it is important to appreciate
the anatomic relationship of the transverse processes to the corresponding spinous processes (Figure 3-19).
Tenderness over articular landmarks is an important potential
sign of JSDSs. Of all the diagnostic signs of JSDS, palpation for
tenderness appears to be the most reliable.244,255,256,382,444-446 However,
joint dysfunction is not always synonymous with joint pain.
Dysfunction may or may not directly cause joint pain. Although
JSDS is commonly associated with pain, chronic dysfunctions may
be nonpainful, but potentially create a region of altered mobility
that can predispose to joint strain and pain elsewhere.
Misaligned articular structures may implicate the presence of
joint subluxation/dysfunction, but apparent joint malpositions may
result from anomaly or compensation without dysfunction. Spinal
landmarks, especially the spinous processes, are prone to congenital
or developmental malformation. Disrelationship between adjacent
spinous processes can be falsely positive and cannot be relied on to
represent true misalignment. Furthermore, the spine functions as
a kinetic chain, and disease or dysfunction at one level may force
adaptational alterations in neutral alignment at adjacent levels.
These sites of compensational change may palpate as being malpositioned (out of ideal neutral alignment), yet have normal pain-free
function. Static bony palpation does not ascertain joint mobility or
the full extensibility of the articular soft tissues and cannot distinguish normal compensation from joint subluxation/dysfunction.
In the spine, the spinous process and interspinal spaces are
commonly palpated for tenderness to screen for a possible level
of segmental pathology or dysfunction. The relationship between
spinous and interspinous tenderness and dysfunction is speculated
to result from reflex sensitivity in tissues with shared segmental
innervation (allodynia) or from mechanical deformation in structures attaching at these bony sites.
Remember that bony tenderness may result from many different pathologic processes such as bone infection, neoplasia, osteo-
porosis, and fractures. In addition, the spinous process may be
tender whether the joint is hypomobile, hypermobile, or unstable. For the previously outlined reasons, suspected malpositions
or bony tenderness must be associated with other clinical signs
before an impression of joint subluxation/dysfunction is formed.
Soft Tissue Palpation
One of the commonly stated diagnostic characteristics of the
manipulable spinal lesion is altered segmental tissue tone and
texture. The major function of soft tissue palpation is to determine the contour, consistency, quality, and presence or absence
of pain in the dermal, subdermal, and deeper “functional” tissue
layers. The dermal layer incorporates the skin; the subdermal layer
incorporates subcutaneous adipose, fasciae, nerves, and blood vessels. The functional layer consists of the muscles, tendons, tendon
sheaths, bursae, ligaments, fasciae, blood vessels, and nerves.
Palpation of the dermal layer is directed toward the assessment
of temperature, moisture, motility, consistency, and tissue sensitivity (e.g., hyperesthesia and tenderness). Palpation techniques
involve light, gentle exploration of the skin with the palmar surfaces of the fingers or thumbs. When manually assessing temperature of superficial tissues, the dorsum of the hands is typically used
(Figure 3-20). Motility and sensitivity of the dermal layer may also
be assessed by the technique of skin rolling (see Figure 3-20).
The subcutaneous and deeper functional layers are explored
for internal arrangement, contour, consistency, flexibility, and
response to pressure. The deeper soft tissues are usually investigated with the fingertips or thumbs (Figure 3-21). Palpation of
paraspinal soft tissues is customarily performed immediately after
bony palpation. The cervical spine is customarily examined with
the patient in the supine or sitting position and the lumbopelvic
and thoracic regions in the prone position.
The palpatory investigation of the functional layer is the decisive element in the soft tissue investigation for signs of joint dysfunction. Suppleness and flexibility of muscle and connective
tissues are important and necessary for proper functioning of
the joint systems of the body. Muscular and myofascial dysfunction are considered to be common factors in the pathogenesis of
somatic and joint pain syndromes.118,447 Segmental tissue texture
T1 to T4
Transverse
process up 1
interspinous
space
T5 to T8
Transverse
process up 2
interspinous
spaces
T9 to T11
Transverse
process at base
of spinous space
Figure 3-19â•… The structural relationship between thoracic spinous
processes and transverse processes.
Soft tissue
elasticity
Skin rolling
Skin temperature
evaluation
Figure 3-20â•… Assessment techniques for evaluating alterations in tem-
perature, tenderness, tone, and texture of the superficial layer of the soft
tissues.
Chapter 3╅ Joint Assessment Principles and€Procedures |
BOX 3-7
Figure 3-21â•… Assessment techniques for evaluating tone and texture
in the deep paraspinal soft tissues using fingertips.
changes may include abnormal hardness, bogginess, or ropiness of
the underlying paraspinal muscles.448 The reliability and accuracy
of palpation to detect muscle dysfunction are not well established
in the scientific literature.121,449
The presence of soft tissue pain and asymmetric tone is regarded
as an important indicator of joint dysfunction.419 Grieve449 suggests that it may be the objective findings of muscle abnormality (palpable nodules, bands, or stringiness) and the presence of
muscle tenderness that represent external evidence of changes in
peripheral tissues related to joint problems. Furthermore, muscle pain is sometimes acute and surprisingly quite unknown to
the asymptomatic patient until made manifest by careful localized palpation. Nilsson382 found acceptable reliability of palpation for cervical erector spinae muscle tenderness using a grading
pain scale of 0 to 3 that incorporated both verbal and nonverbal responses from the patient. Christensen and colleagues450 also
reported good interexaminer reliability for thoracic paraspinal
tenderness. The interexaminer agreement for the detection of tissue texture changes within muscle tissue appears to be less reliable
than the detection of tenderness.121
In health, normal neuromuscular coordination is accepted as
unremarkable; only in dysfunction does the underlying complexity of movement become apparent and the disturbance of reciprocal muscle action become manifest.449 Moreover, abnormal soft
tissues patterns and presentations may persist after joint function
has been restored. Although chronic muscle imbalance has a role
in initiating and perpetuating joint problems and somatic pain, it
may be secondary to stresses imposed by ligamentous failure, denervation, or reflex inhibition from pain. Adjustments of the joint
without attention to the supporting and controlling effects of the
soft tissues will likely result in recurrence of joint dysfunction.
Soft tissue asymmetries may also result from congenital or
developmental variations or be the product of nonmanipulable
disorders. Accordingly, any noted soft tissue abnormalities must
be assessed within the context of a broader examination to be clinically significant. Instructions and tips on the use of static bony
and soft tissue palpation are included in Boxes 3-7 and 3-8.
Motion Palpation
Motion palpation is a procedure in which the hands are used to
assess mobility of joints. It is a skill that depends not only on
psychomotor training but also on an understanding of the local
functional anatomy, biomechanics, and pathomechanics. Each
67
How to Use Palpation Tools
Use the least pressure possible. Your touch receptors are
designed to respond only when not pressed too firmly.
Experiment with decreasing pressure instead of increasing
pressure, and your tactile perception may improve.
Try not to cause excessive pain if possible. Pain may induce
protective muscle splinting and make palpation more
difficult.
Try not to lose skin contact before finishing palpation of the
area.
Use broad contacts whenever possible. For deep palpation,
use broad contacts to reach the desired tissue, then
palpate with your palpation finger, keeping the overlying
tissue from expanding with the other fingers of your
palpation hand.
Close your eyes to increase palpatory perception.
BOX 3-8
Palpation Hints and Comments
Concentrate on the area or structure you want to palpate; do
not palpate casually.
Do not let your attention be carried away by unrelated
sensations.
Concentrate on your fingers; do not feel what you see or
expect to feel.
Keep an open mind and do not deceive yourself; never let
your mind “out palpate” your fingers.
Establish a palpation routine and stay with it.
Take every opportunity to add to your tactile “vocabulary”
through comparative experiences.
individual extremity joint and spinal region has its unique patterns and ROMs that must be learned if the chiropractic student
is to master the art of motion palpation.
Motion palpation covers a collection of manual examination
procedures that are customarily divided into techniques designed
to assess active, passive, and accessory joint movements. Active
movements are internally driven and are the result of voluntary
muscle contraction. During active movement assessment, the
doctor may help guide the patient through a given motion, but
the patient provides the muscular effort necessary to induce joint
movement. The range of active joint movement is determined by
the joint’s articular design and the inherent tension and resilience
in its associated muscular, myofascial, and ligamentous structures.
Greenman337 has labeled the end point of active joint movement
as the physiologic barrier. (Figure 3-22).
In contrast, passive joint movements are involuntary movements. With the patient in a relaxed position, the examiner carries
the joint through its arc of available motion. The range for passive
joint movement is somewhat greater than the range for active joint
movement because of decreased muscle activity (see Figure 3-22).
The range of passive joint movement also depends on articular
design and flexibility of related articular soft tissues.
68
| Chiropractic Technique
PASSIVE ROM
Joint injury
(sprain, orthopedic
subluxation, dislocation)
ACTIVE ROM
Physiologic
barrier
EPZ
EB
PS
Anatomic
Joint trauma
limit
or pathology
JP
neutral
SEPARATION (mm)
6
5
4.5 mm
4
2
1.8 mm
Figure 3-22â•… Joint motion starting from a neutral position. The first
motion evaluated from a neutral starting position is joint play (JP). JP is a
component of active and passive joint motion. It is induced by the examiner and represents the give and flexibility of the joint capsule. Active
range of motion (ROM) represents the movement that is actively produced by the patient. Passive ROM represents the motion produced by
the examiner. It is usually slightly greater in range because the patient’s
muscles are not active but relaxed. Toward the end of passive movement
the end-play zone (EPZ) is encountered. The EPZ represents the increased
resistance that is felt as the joint’s elastic limits are reached. The elastic
barrier represents the end point of the joint’s elastic limits and the point at
which additional movement is only possible after joint surface separation.
Joint surface separation at this point usually occurs only after joint cavitation. After cavitation, the paraphysiologic space (PS) extends the passive
ROM. At the end of the PS, the joint’s anatomic limits are encountered.
If the joint is carried beyond its anatomic limit, injury results.
As the limits of passive joint movement are approached, additional resistance is encountered as the joint’s elastic limits are challenged. Movement into this space, the EP zone (EPZ) (see Figure
3-22), may be induced by forced muscular effort by the patient
or by additional overpressure (EP) applied by the examiner. If the
forces applied at this point are removed, the joint springs back
from its elastic limits. Movements into this region are valuable in
assessing the elastic properties of the joint capsule and its periarticular soft tissues.
Movement beyond the EPZ is possible, but usually only after
the fluid tension between synovial surfaces has been overcome.
This process is typically associated with an articular crack (cavitation). Sandoz50 has labeled this as the zone of paraphysiologic
movement and identified its boundaries as the elastic and anatomic
barriers (see Figure 3-22). In circumstances in which the joint
capsule is especially flexible, joint separation may occur without
cavitation. The loose capsule allows for separation without fluid
tension build-up between articular surfaces.451
The labeling of the postcavitation increase in joint movement
as paraphysiologic can be misleading. Although the paraphysiologic space (PS) aptly identifies an area of increased movement, it is still within the joint’s elastic range and anatomic
limits. Movement into this space does not induce joint injury.
However, if the outer boundaries (anatomic limits) of the PS are
breached, then plastic deformation and joint injury may occur50
(Figure 3-23).
5.4
mm
Paraphysiologic zone
Repeat
loading “CRACK”
3
Rest
EPZ  End-play zone
EB  Elastic barrier
JP  Joint play
PS  Paraphysiologic space
Initial unloading
Initial unloading
Preliminary tension
2
4
6
8
10
Elastic barrier
of resistance
12
14
16
18
Limit of anatomic
integrity
LOAD (Kg  N/10)
Figure 3-23â•… Increased movement that occurs after joint cavitation.
The solid line represents the initial loading of the joint and the increased
joint separation and movement that occurs only with cavitation. The broken line illustrates that repeated loading of the joint will induce the same
amount of joint separation without joint cavitation.
Figure 3-24â•… Assessment of segmental range of
3-24
motion (e.g., midthoracic left axial rotation). The small
circle located on the skeletal drawing represents the location of the thumb
contact traversing the left side of the T10 and T11 spinous processes.
Restrictions of joint motion may occur at any point within the
joint’s ROM. They may be minor or major in nature and encountered within the joint’s active or passive range. Restrictive barriers
encountered within the joint’s active ROM are primarily a result of
myofascial shortening.337 This may be a product of muscle splinting, hypertrophy, aging, or contracture. Restrictive barriers to
movement at the end range of passive motion are more indicative
of shortening in the joint capsule and periarticular soft tissues.
During the performance of motion palpation, the examiner
characteristically uses one hand to palpate joint movement (palpation hand) while the other hand (indifferent hand) produces or
guides movement. The palpation hand establishes bony or soft tissue contacts over the joint as attention is directed to the assessment
of joint range, pattern, and quality of movement (Figure 3-24).
Chapter 3╅ Joint Assessment Principles and€Procedures |
When assessing joint motion, the palpator is evaluating the quality and quantity of movement from the starting or zero point to
the end range of passive movement. In spinal evaluation, the landmarks commonly used are the spinous processes, articular pillars,
transverse process, rib angles, and mammillary processes. During
spinal palpation the examiner can attempt to assess the ROM of a
single spinal motion segment or take broader contacts to assess a
spinal region and several joints at a time.
Accessory Joint Motion
Accessory joint movements are necessary for normal function.
They are small, involuntary movements made possible by the
give within the articular soft tissues of each synovial joint. Joint
surfaces do not form true geometric shapes with matching
articular surfaces. As a result, movement occurs around a shifting axis, and the joint capsule must allow sufficient play and
separation between articular surfaces to avoid abnormal joint
friction.
Accessory joint movements are evaluated by the procedures
of JP and EP.48,53 EP evaluation is the qualitative assessment of
resistance at the end point of passive joint movement, and JP is
the assessment of resistance from a neutral or loose-packed joint
position.61 Both motions depend on the flexibility (play) of the
articular soft tissue and are not distinguished by some authors.48,53
Rather, EP is considered to be JP delivered at the end range of
joint motion.
Joint Play. JP assessment is the qualitative evaluation of the joint’s
resistance to movement when it is in a neutral or loose-packed position. The loose-packed position allows for the greatest possible play
between the joint surfaces and the best opportunity to isolate the
joint capsule from the periarticular muscles (see Figure 3-22). JP
assessment therefore is helpful in the isolation and differentiation of
articular-based pain and dysfunction from nonarticular soft tissue
disorders. It has also been proposed as an evaluative procedure for
the clinical assessment of joint instability; it has demonstrated some
validity in detecting excessive translational movements that may
result from derangement of the joint’s stabilizing structures.167,169
JP is assessed by placing the tested joint in its loose-packed
position, establishing palpating contacts over the joint, and
inducing gentle shallow springing movements (Figure 3-25).
Figure 3-25â•… Assessment of joint play movement:
3-25
posteroanterior glide, midthoracic segment. Circles
indicate location of fingers over joints to be assessed.
69
This is most commonly done in the spine by placing the patient
in a prone position and applying a P-A force. The true loosepacked position may not be achievable in the acutely injured
or pathologic joint, and attempts to force a loose-packed position should be avoided. In such circumstances, the chiropractor
should attempt to find the loosest possible pain-free position.
JP movements are small in magnitude and vary by spinal region
or extremity joint. It is therefore essential that the examiner,
through practice, develop an appreciation for the regional and
specific qualitative differences. As mentioned previously, this
procedure has demonstrated good reliability for reproduction
of pain (joint provocation and challenge) but poor reliability of
determining hypomobility.246
JP procedures include methods in which the palpatory contacts
are established over the joints to be assessed. Methods that involve
contacts on both sides of the spinous process can be applied with
opposing springing movements in attempts to specifically isolate
a particular level of pain or dysfunction (Figure 3-26). During the
performance of JP, the chiropractor should check for the presence
or absence of pain, the degree of encountered resistance, and the
quality of movement. JP should not induce pain; some resistance
to movement should be encountered, but the joint should yield
to pressure and spring back, producing short-range movements.
Production of pain or increased resistance to JP movements suggests that the joint and its articular soft tissue may be the source of
the patient’s local spine complaint.
End Play. During EP assessment, the chiropractor is concerned with the symptomatic and qualitative assessment of
motion through the EPZ (Figure 3-27). The EPZ is characterized by a sense of increasing resistance as it is approached (first
stop) and a second firmer resistance (second stop) as its limits
are approached (see Figure 3-27). In a healthy joint, it should
be pain-free.
EP is assessed by applying additional overpressure to the specified joint at the end range of passive movement. During spinal EP
assessment, a gentle springing force is typically induced through
the palpation and indifferent hand contacts (see Figure 3-27). To
execute end feel, the chiropractor should evaluate the point at
which resistance is encountered, the quality of that resistance, and
whether there is any associated tenderness.
Figure 3-26╅ Assessment of joint play �movement:
3-26
counter-rotation between T4 and T5. Circles indicate placement of thumb contacts on adjacent spinous processes. Figure
illustrates challenging the joint into left rotation.
70
| Chiropractic Technique
End-Feel
zone
Final
stop
First
stop
Start
Figure 3-27â•… Assessment of lateral flexion end
3-27
play motion. The circle between L3 and L4 on the
skeletal drawing represents the location of the thumb contact against the
lateral surface of the spinous process.
BOX 3-9
EP evaluation is an important element in the assessment of
joint function. In spinal joints, it has been reasoned that EP
may be more informative than procedures designed to assess the
ROM of individual spinal joints. This is based on the premise that qualitative changes in movement may be more reliably evaluated than quantitative changes, especially in the spine
where the joints are deep and less accessible to palpation and
the �segmental ROM is normally small.452 A recent qualitative
literature review �evaluated this question and did not confirm a
�significant advantage for EP over segmental ROM. The authors
did note an advantage to EP over segmental ROM, but it did not rise
to the level of being statistically significant.391
However, the number of quality studies is very limited and further evaluation of EP reliability and validity as compared with segmental ROM is needed before conclusive statements are made.391
Each spinal region or extremity joint has characteristic EP
qualities that are determined by the local bony and soft tissue
anatomy (physiologic end feel). For example, elbow extension has
a hard, bony end feel produced by the bony impact of the olecranon on the humerus, and elbow flexion has a soft springy end
feel produced by the impact, or compression, of soft tissues on
the arm and forearm. What may be a normal EP at one joint may
be a pathologic EP at another. A hard, bony EP to elbow flexion
might indicate a fracture or an intra-articular blockage, and a soft,
springing EP to elbow extension might indicate joint effusion.
Physiologic and pathologic EPs have been tabulated for the spine
and extremity joints and are outlined in Box 3-9.
Normal and Abnormal End Feels
CAPSULAR
Firm but giving; resistance builds with lengthening, like
stretching a piece of leather
Example: lateral flexion of spine; external rotation of
shoulder
Abnormal example: capsular fibrosis or adhesions leading to a
capsular pattern of abnormal end feels, see Table 3-5
LIGAMENTOUS
Like capsular, but may have a slightly firmer quality
Example: knee extension
Abnormal example: noncapsular pattern of abnormal
resistance as a result of ligamentous shortening
SOFT TISSUE APPROXIMATION
Giving, squeezing quality; results from the approximation of
soft tissues; typically painless
Example: elbow flexion
Abnormal example: muscle hypertrophy, soft tissue swelling
BONY
Hard, nongiving abrupt stop
Example: elbow extension
Abnormal example: bony exostosis, articular hypertrophic
changes
MUSCULAR
Firm but giving, builds with elongation; not as stiff as capsular
or ligamentous
Normal example: hip flexion
MUSCLE SPASM
Guarded, resisted by muscle contraction; muscle reaction
should be felt. The end feel cannot be assessed because of
pain or guarding
Abnormal example: protective muscle splinting that is a result
of joint or soft tissue disease or injury
INTERARTICULAR
Bouncy, springy quality
Abnormal example: meniscal tear, joint mice
EMPTY
Normal end feel resistance is missing; end feel is not
encountered at normal point, or the joint demonstrates
unusual give and deformation
Abnormal example: joint injury or disease leading to
hypermobility or instability
Chapter 3╅ Joint Assessment Principles and€Procedures |
Loss of normal EP elasticity is thought to be indicative of disorders within the joint, its capsule, or periarticular soft tissue.
Abnormal EP resistance or increased pain is considered a significant finding in the determination of JSDSs and directing adjustive
vector. Adjustive therapy is commonly applied in the direction of
encountered resistance in an attempt to restore normal mobility.
Cyriax22 has suggested that EP assessment is particularly valuable in isolating the integrity of the joint capsule. He has proposed
that injuries or disorders that lead to contractures of the joint capsule will lead to predictable patterns of JP or EP restrictions in
multiple ranges. Each joint purportedly has its own characteristic capsular pattern of restricted movement that indicates capsular involvement (Table 3-4). Injuries or contractures in only one
aspect of the capsule do not necessarily follow this typical pattern
and may affect movement in only one direction.
Loss of normal EP resistance (empty end feel) is also clinically
significant because it is a potential manifestation of joint hypermobility or instability. Injuries or disorders that lead to elongation
of the joint’s stabilizing structures may lead to a loss of normal
end-range resistance. Although an empty EP is indicative of possible clinical joint instability, segmental muscle splinting in the
symptomatic patient may mask its presence.
TABLE 3-4
Capsular Patterns
Joint
Pattern*
Spine
Ipsilateral rotation and
contralateral lateral
flexion
Internal rotationabduction,
flexion-extension,
adduction-external
rotation
Flexion (great)-extension
(slight)
Dorsiflexion-plantar
flexion
Flexion-extension
Hip
Knee
Ankle
Metatarsophalangeal
joint
Interphalangeal joint
Shoulder
Elbow
Distal radioulnar joint
Radioulnar carpal joint
Midcarpal joint
Thumb carpometacarpal
joint
Metacarpophalangeal
joint
Flexion-extension
External rotationabduction–internal
rotation-flexion
Flexion-extension
(pronation and
supination, full range)
Pronation-supination
Flexion-extension
Extension-flexion
Abduction-extension
Flexion-extension
*Patterns are in order of decreasing stiffness, except the spine, in which either is possible.
71
Joint Challenge (Provocation)
The assessment of pain during the application of JP and EP is
often referred to as joint challenging or joint provocation. It is commonly used to isolate joint pain and to determine which segmental
tissues placed under tension may be sensitive to mechanical deformation and responsible for the patient’s pain. It often involves
methods that attempt to isolate a given joint by applying counterpressure across the joint.
In the spine, the counter-opposing pressures are commonly
applied against the spinous processes. During this procedure, the
vertebrae are stressed in different directions from their neutral
positions, and directions of increased and decreased pain are noted
(see Figure 3-26). Pain during movement is theorized to result
from increased tension on injured or inflamed articular tissue. The
absence of pain during movement indicates that tissues tractioned
(challenged) in the direction of movement are not injured.
Provocation of joint pain during movement assessment in combination with tests for mobility have demonstrated promising
results.389,416,453 Recent studies have indicated that P-A springing of
the spine has good interexaminer reliability for the reproduction of
pain, but mixed reliability for hypomobility. Some have suggested
that the provocation of pain during joint movement assessments is
the element responsible for reliably and accurately identifying symptomatic joint dysfunction.394,418 Others have suggested that pain provocation is an important tool, but they are concerned that reliance on
this procedure would lead to an increased incidence of false-positive
results.419 Spinal pain is often poorly localized and commonly associated with sites of referred pain. The site of maximal tenderness is not
always the source of the pathology or JSDSs. Chiropractic theory
implies that joint restrictions (fixations) are not necessarily symptomatic. Marked reduction in movement at one spinal level may
induce increased compensatory hypermobility at other joints that
may be more symptomatic than the restricted joints.
In addition, this procedure has been proposed as a method for
determining the alignment of joint subluxations and direction of
appropriate adjustment. The assumption is that pain is increased
when subluxated vertebrae are pushed in directions that increase
the misalignment (into lesion) and that pain is decreased in the
direction that reduces the misalignment (out of lesion). For example, pressure exerted toward the right against the left side of a
right-rotated T4 spinous process (left rotating the joint) purportedly would increase the misalignment and induce pain (see Figure
3-26). Pressure exerted toward the left, against the right side of
the T4 spinous process would decrease the misalignment and not
elicit discomfort. This approach has value in the evaluation and
treatment of the acutely injured patient when the clinician is trying to determine how to induce joint distraction or reduce a traumatic subluxation without causing more tissue damage. However,
whether this principle applies equally in all cases of joint subluxation/dysfunction is questionable.
If the rule of pain-free manipulation were applied in the case
of post-traumatic joint dysfunction resulting from periarticular
soft tissue contractures, would it accurately determine the appropriate direction of adjustment? Manual therapy applied in this
scenario would logically be directed to stretch the shortened
and contracted tissue. Tensile stretch applied to contracted and
72
| Chiropractic Technique
inelastic tissue commonly induces some discomfort. Applying the
rule of pain-free manipulation in this scenario would lead to an
adjustment in the direction opposite the restriction. In this circumstance, the adjustment should be made in the direction of
encountered joint restrictions, even if it is associated with some
tenderness. Without attention to patient history and directions
of encountered abnormal resistance, proper adjustive care may
be missed.
From this discussion, the following generalizations about adjustive treatment for established joint dysfunction can be made:
• Adjustments should never be applied in directions of marked
pain and splinting.
• Adjustments should not be applied in the direction of
prestress that causes a peripheralization (radiation) of pain.
• Adjustments may be applied in directions of increased
tenderness if associated with abnormal increased resistance.
• Adjustments may be applied in the nonpainful direction if
directed to reduce joint subluxation or induce pain relief.
The procedures of segmental motion palpation have focused on
the detection of joint pain and mobility, and although restricted
joint and accessory joint motion may be indicative of joint dysfunction and sufficient evidence for joint manipulation, clinicians must guard against perceiving it as a diagnostic panacea.
Isolation of a painful joint does not determine the cause of the
pain or possible disease. Motion palpation cannot be used in
all clinical situations (e.g., acute joint pain or injury), and certain disease states capable of producing joint restrictions may
produce pathophysiologic change that contraindicates adjustive
therapy.
As mentioned previously, segmental motion palpation is
also subject to error and therefore should not be applied in
isolation. However, Phillips and Twomey454 did find that
motion palpation was highly sensitive and specific for detecting a symptomatic lumbar segment when they incorporated
a subjective pain response from the patient. Nonetheless,
the determination of joint dysfunction should be made in
conjunction with other clinical findings. No one evaluative tool should be the sole source for therapeutic decisions. Goals, principles, and tips for conducting motion
palpation are outlined in Boxes 3-10, 3-11, and 3-12.
Percussion
Percussion plays a secondary role in the assessment of joint dysfunction. The area of greatest application is probably the spine,
where a positive response may help localize a painful motion
�segment. Spinal percussion may be applied by the hypothenar
of the clinician’s hand or with a reflex hammer (Figure 3-28).
In both circumstances, the clinician should apply a gentle percussive force sequentially to the spinous processes. A marked or
persistent pain response to percussion may indicate an underlying fracture or a nonmechanical pathologic condition, whereas
a mild pain response may indicate local irritation and dysfunction. When the response indicates a potentially serious disease,
additional radiographic or laboratory procedures are necessary
to differentiate a manipulable lesion from a nonmanipulable
one.
BOX 3-10 Goals of Motion Palpation
To assess the following:
Quantity: How much does the joint move?
Quality: How does the joint move through its range of
motion?
End feel: At what point is end feel encountered, what is the
quality of resistance, and at what point does the motion
stop?
Joint play: What is the quality of resistance? Is there too
much or too little?
Symptoms: Are there changes in the amount or the location
of pain during assessment and motion?
BOX 3-11 Principles of Motion Palpation
Joint movement is tested by assessing how two bony joint
partners and their soft tissues move in relation to each
other.
When evaluating segmental movement, test one movement
at one joint around one axis in one plane on one side of
neutral whenever possible.
Develop a pattern and test each motion segment being
evaluated in sequence.
Move through the entire available range of motion; start and
end at neutral. The singular assessment of end feel is an
exception to this principle.
Motion must be performed slowly and smoothly with the
minimal force necessary.
Compare mobility with the contralateral side and adjacent
segments.
BOX 3-12 Motion Palpation Tips
Do not let soft tissue movement and tension changes fool
you. They are important indicators of the amount of
underlying joint movement, but it takes experience to
evaluate them.
Concentrate and be alert from the beginning; valuable
information is often gained early in the range of motion.
Where possible, contact both joint partners of the joint
being evaluated. This can be done by using two fingers
of the same hand, one finger of each hand, or one finger
palpating both joint partners simultaneously, thereby
crossing the joint space.
Your patient has to feel comfortable, relaxed, and safe.
Do not produce too much movement with your palpation
hand. It helps focus your palpation forces, but it must also
be free to palpate.
Your palpating finger applies minimal pressure, applies
enough pressure so as not to lose firm contact with the
bony prominence on the moving joint partner, and is an
impartial observer.
Chapter 3╅ Joint Assessment Principles and€Procedures |
73
Figure 3-28â•… Percussion of the spinous processes with a reflex hammer.
Muscle Testing
Motor changes are characteristic of many neuromuscular conditions, making tests for muscle length and strength an integral part
of the examination process. The testing of muscle structure and
function requires knowledge of joint motion, origin and insertion of muscles, agonistic and antagonistic actions, and the ability
to palpate the muscle or its tendinous attachments for tone and
texture changes.
Muscle strength testing incorporates tests for strength and
endurance. Endurance can be evaluated by the patient’s ability to perform repeated movements or maintain static postures.
Normative values for repetitive squatting, sit-ups, prone arch-ups,
and sustained prone back extension have been established and are
valid measures for measuring spinal fitness and treatment outcomes (Figure 3-29). Strength testing can be evaluated manually
or with the aid of specialized equipment, such as computer-aided
dynamometry (e.g., Biodex, Cybex, Med-X, and Promotron).
Manual muscle testing procedures have been extensively described
for isolating specific muscle function.455 Manual resisted muscle tests
are performed to assess the strength and sensitivity of muscle and its
tendinous attachments (Figure 3-30). Any noted muscle weakness
should be recorded and graded on a five-point system (Box 3-13).
Muscle testing procedures are numerous, and descriptions of individual procedures are beyond the scope of this text. The reader is
encouraged to refer to any number of excellent texts for detailed
descriptions on how to perform individual muscle tests. Pain with
muscle contraction may indicate a muscle injury, a joint injury, or a
combined muscle and joint injury. Pain with isometric contraction
generally indicates a muscle injury rather than a capsular injury.22
Isometric muscle contraction, however, may still produce some degree
of joint compression and capsular tension. To differentiate a purely
muscular injury from a capsular injury, passive joint movement and
compression must be performed and their results compared with the
response elicited during isometric muscle contraction.19,22
Figure 3-29â•… Repetitive arch-ups from a flexed position.
Figure 3-30â•… Resisted muscle tests evaluate strength and sensitivity at
the tendinous attachments (e.g., left psoas muscle test.)
A capsular injury produces pain with passive and active movements as the capsule is elongated. A purely muscular injury produces pain with muscle contraction and muscle �elongation, but
passive shortening of myofascial tissue should not be painful.
The small segmental muscles of the back are not independently
accessible to palpation or specific muscle tests. Injuries to the deep
segmental muscle of the back cannot be easily differentiated from
other injury or dysfunction of the spinal joints. Therefore, muscle
testing in the back is used primarily to differentiate injuries to the
large, nonsegmental back muscles from dysfunction or injury to
the spinal joints and their associated soft tissues.
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| Chiropractic Technique
BOX 3-13
ive-Point Grading System for
F
Muscle Weakness
5—Patient can maintain position against gravity and
maximum examiner-applied resistance.
4—Patient can maintain position against gravity and
minimal examiner-applied resistance.
3—Patient can maintain position against gravity.
2—Patient can move through arc of motion when gravity is
lessened.
1—Muscle contraction is visible or palpable, but there is no
movement of part.
0—There is no palpable or perceivable muscle contraction.
Within the chiropractic profession, manual muscle testing has
also been used to evaluate spinal joint function and the health and
function of other organ systems of the body. Central to the use of
these procedures is the premise that changes in muscle strength
can be affected by functional and pathologic changes in other
�tissues of the body.456 Muscle testing in this capacity is controversial and typically is used by professionals who use procedures associated with the technique of applied kinesiology.
The applied kinesiology technique proposes the use of manual
muscle tests coupled with the use of applied vertebral pressures
to determine the level and direction of spinal subluxation. This
procedure is commonly referred to as the vertebral challenge.456
The vertebral challenge involves digital pressure applied by the
examiner against spinal bony landmarks as the examiner simultaneously evaluates the strength of a selected muscle. The tested muscle is
evaluated for its ability to resist torque and maintain a locked position.
If the muscle gives way under pressure, the test is considered positive
and the level of spinal contact is considered a site of dysfunction.
During testing, the contacted vertebra is pushed (challenged) in
different directions. If the muscle gets weak, the assumption is that
the segment is being directed more into a subluxated position. If the
muscle remains strong or gets stronger, the assumption is that the
vertebra is being pushed out of its subluxated position. It is believed
that all muscles of the body are temporarily inhibited by stimulation
of subluxated segments. Therefore, any muscle of the body can be
selected as the “indicator muscle” during the use of this procedure.
This procedure is often performed as a rebound challenge. This
procedure is based on the premise that subluxation syndromes are
associated with hyperactivity in segmental muscles. The rebound
challenge is performed by the application and quick release of spinal pressure.456 During testing the contacted vertebra is pushed
(challenged) in different directions. The rebound phase is represented by the quick release of applied pressure.
If this method is used in a direction that stretches hyperactive
muscle, it is assumed the hyperactive muscle will contract against a
quick stretch and pull the vertebra farther into its malpositioned state
during the rebound phase. If the vertebra is pulled farther in the direction of malposition, a weak muscle response is predicted. Therefore, a
weak muscle response during the rebound phase indicates that a segment should be adjusted in the direction of the applied testing force.
The vertebral challenge and rebound vertebral challenge have
not been extensively evaluated. The few studies that have been con-
ducted have demonstrated poor intraexaminer and interexaminer
reliability and no responsiveness to adjustive treatments.457,458
Provocative (Orthopedic) Tests
Provocative testing covers a wide range of manual testing procedures, many of which have already been discussed. Provocative procedures are tests that are conducted to reproduce a specific sign or
accentuate pain. The major purpose of testing is to locate the anatomic site responsible for producing the patient’s pain. Provocative
orthopedic tests represent a separate category of named procedures
designed to use movements or positions to localize the source and
nature of the patient’s disorder. The procedures are commonly
labeled with the name of the original innovator (e.g., Kemp test) or
carry a descriptive label (e.g., straight leg raise test).
Named provocative orthopedic procedures are not commonly
cited because many procedures are not applicable to the identification of spinal subluxation/dysfunction syndromes. They are
helpful in identifying the anatomic location of painful complaints
and discriminating between mechanical, nonmechanical, and
NR pain. They have demonstrated less value in discriminating
between conditions.297 Orthopedic tests are also helpful in identifying possible contraindications to adjustive therapy and monitoring patients’ response to treatment.459 Evans provides an excellent
description of spine and extremity provocative orthopedic tests,
including how they are performed and interpreted.459
Radiographic Analysis
Radiographic assessment and determination of joint subluxation
have been an integral part of chiropractic evaluation since the early
1900s.335,460,461 Ever since Sausser first made a full-spine exposure,
the chiropractic profession has desired and sought out methods for
marking x-ray films to identify manipulable lesions. The history
of chiropractic marking procedures dates back to 1910462 when it
was first introduced in the Palmer School curriculum.
The early use of diagnostic x-ray examinations in the chiropractic profession centered on the assessment of biomechanical relationships and the measurement and description (listing) of spinal joint
malpositions. To that end, the profession and many of its individual
technique innovators have developed specific radiographic measurement techniques (spinography) designed to quantify and classify spinal malpositions and subluxations (Figure 3-31).32,128,461,463-467
Although many “systems” to detect static subluxations on x-ray
films have emerged over the years, these procedures remain controversial. Criticism and failure of the static x-ray marking systems
come from trying to use quantitative measures on landmarks that
vary and that are subject to geometric distortion.468 Moreover, the
spine and its functional units are living, moving, and dynamic structures that depend on complex relationships among bones, ligaments,
and muscles. Plain-film x-ray examination does not evaluate movement of the spine, nor does it directly assess the soft tissues.
Although the limitations of radiographic marking systems are
well established469 (Box 3-14), static alignment abnormalities can
have some significance when taken in context with other clinical,
historical, and laboratory findings. In recent years, more emphasis has been placed on the dynamic concepts of the subluxation
Chapter 3╅ Joint Assessment Principles and€Procedures |
75
L
A
B
D
C
E
F
G
Figure 3-31â•… Static spinographic measures. A, Anteroposterior open mouth. B, Anteroposterior lower cervical. C, Anteroposterior thoracic
and D, anteroposterior lumbar and pelvis. E, Lateral cervical neutral. F, Lateral thoracic and G, lateral lumbosacral.
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| Chiropractic Technique
BOX 3-14
imitations of Radiographic Marking
L
Systems
Anatomic asymmetry
Radiographic magnification
Radiographic distortion
Radiographic malpositioning
Static analysis of dynamic motion segments
Inaccuracy of instruments
Insignificant findings
BOX 3-15
ationale for Radiography in
R
Chiropractic Practice to Establish a
Clinical Diagnosis
To evaluate biomechanics and posture
To identify anomalies
To screen for contraindications
To monitor degenerative processes
complex, in some cases totally disregarding static biomechanical
relationships. Sandoz470 feels that this shift of emphasis is counterproductive. He suggests considering the mechanical, static,
and dynamic concepts in harmony with the neurologic and reflex
elements of spinal subluxation/dysfunction.
Over the years, the role of x-ray examination has been modified according to scientific and technical developments, as well as
to philosophic tenets and beliefs. Sherman462 summarized the clinical rationale for the use of x-ray examination in chiropractic (Box
3-15). Evidence-based diagnostic imaging practice guidelines have
been developed.471-474 They are intended to assist primary care providers, interns, and residents in determining the appropriate use of
diagnostic imaging for specific clinical presentations. In all cases,
the guidelines are intended to be used in conjunction with sound
clinical judgment and experience. The goal of these guidelines is
to avoid unnecessary radiographs, increase examination precision,
and decrease health care cost without compromising the quality
of care.471 Ammendolia and co �workers475 surveyed chiropractic
colleges around the world to evaluate whether imaging guidelines
were being taught and adhered to. The results of this study suggest that instruction provided at most chiropractic schools appears
to adhere to evidence-based guidelines for LBP with respect to
the use of routine radiography, full-spine radiography, and oblique
views, but there appears to be some disparity between instruction
and existing evidence for the use of radiography in acute LBP.475
Spinal X-ray Examinations
Historically, the use of spinal radiography examinations in chiropractic centered on the detection and quantification of the intervertebral misalignment.476 Proponents of radiographic evaluation
for the detection of spinal subluxations claim that x-ray examinations are the best method for accurately determining the level and
direction of vertebral malposition.460 They contend that chiropractors who do not use radiography to evaluate spinal subluxations
are at a disadvantage in determining and delivering indicated
and safe adjustments. In the 1970s, this view produced a policy
requiring chiropractors to demonstrate radiographically the presence of spinal subluxations to treat and receive reimbursement for
Medicare patients. This policy has been recently modified and was
rescinded in 2000 in favor of the PART multidimensional index
for joint dysfunction.
Preadjustive x-ray examinations are also rationalized as necessary
because the treatment incorporates the use of force. It is reasoned
that the integrity and mechanical characteristics of the spine should
first be screened radiographically before adjustments are made.476
This position is controversial and unsubstantiated. Screening
x-ray examinations taken without clear clinical guidelines have
not correlated with improved diagnosis or patient outcome.477,478
Furthermore, thrusting forms of manipulation have been used
safely for centuries without the aid of x-ray examinations.
Spinal x-ray examinations are usually taken with the patient in an
upright, weight-bearing position and should consist of two views,
typically an anteroposterior and lateral projection. Traditionally,
the alignment of the upper vertebrae is compared with that of the
lower vertebrae, and any malpositions are recorded.32,128,460
Full-spine radiographs are used primarily for biomechanical
evaluation, including the assessment of individual motion segment alignment. Full-spine evaluations provide an integrated view
of spinal biomechanics and are the method of choice in the evaluation of spinal scoliosis. Full-spine radiographs, however, compromise bony detail and should not be used as a routine procedure for
the assessment of suspected local pathologic conditions.469,479,480
“The clinical justification for the full-spine radiograph must
insure that the benefit to the patient is greater than the radiation hazard. The film must be of such quality that the presence
or absence of pathology can be determined.”481 When indicated,
consideration should be given to full-spine posteroanterior projections to improve visualization of the lumbar IVD spaces and to
minimize exposure to the ovaries and breasts.31,461
Although the majority of the profession uses some form of
radiographic measurement and assessment of spinal subluxation,
there is considerable controversy as to whether radiographic evaluation should play a significant role in the diagnosis of spinal
subluxation syndromes.* Claims of accuracy in detecting minor
joint malpositions may not be supportable against the technical
limitations of radiography.† Inherent radiographic magnification
and distortion, patient positional errors, and the exactness of the
marking procedures are common concerns.
The lack of a consensus on the definition, pathophysiology,
and pathomechanics of spinal subluxations further complicates
the debate and analysis of x-ray marking procedures. Therefore,
the clinical significance of these measurements is controversial and
suspect. Radiographic measures should not be the primary criteria
used to perform chiropractic care.489 However, if there were a clinical indication for taking a radiograph, it would be imprudent not
to evaluate the x-ray examinations for biomechanical relationships
and look for correlations to other clinical findings.
*References 335, 461, 463, 469, 479, 480, 482, 483.
†
References 335, 461, 463, 479, 481, 484-488.
Chapter 3╅ Joint Assessment Principles and€Procedures |
The process of critically evaluating radiographic marking procedures has only begun in the last several decades.335,478,490-495 The
process is in its infancy, and a limited number of studies have
been conducted. A significant number of procedures have yet to
be evaluated. Although it is difficult to draw firm conclusions, it is
possible to briefly summarize the present state of affairs.
First, many of the radiographic marking procedures used to
evaluate segmental spinal alignment can be reliably performed.*
However, most of the reliability studies do not include a full evaluation of all the steps involved in performing and determining
segmental alignment. Many of the studies did not include patient
positioning. Consequently, at this time it is difficult to conclude
whether x-ray marking procedures are or are not reliable for identifying spinal motion segment subluxations.469
Although recent attempts have been made to address issues of
spinographic reliability, very little has been done to investigate the
validity of radiographic measurement in diagnosing and treating
spinal dysfunction.338,470,476-478,496,497
Spinal displacement analysis has not demonstrated the ability
to identify an established clinical entity nor demonstrated its value
as an independent outcome measure. The validity and clinical
usefulness of static marking procedures for identifying treatable
motion segment misalignment have not been demonstrated.488
A retrospective case analysis performed in 1990 identified only
one postmanipulation segmental spinographic change, that being
a reduction in retrolisthesis. There was no identified change in
cervical lordosis, sacral base angle, lumbar lordosis, scapular angle,
or Cobb angle.489 Yi-Kai and coworkers504 investigated the relationship between radiographic signs of subluxation in the cervical spine and their clinical diagnostic value. They concluded that
there was little evidence to support the contention that signs of
subluxation in the cervical vertebrae are diagnostically significant
in identifying individuals with cervical pain. In addition, static
marking procedures have not been found to discriminate between
those with back pain and those without back pain.338,505
Harrison et al483 reviewed the literature on the reliability and
clinical value of spinal displacement analysis in plain-film x-ray
examinations, concluding that x-ray line drawing is a reliable
and effective outcome measure. The conclusion is based on their
�assertion that there is an ideal normal spinal configuration based
on a mathematical model and that radiographic marking procedures can identify real spinal displacements. However, the vast
majority of cited reliability studies were on curve measurements,
not spinal segment position.
Haas and colleagues469 challenged Harrison and colleagues
conclusions483 by questioning the biologic plausibility of an ideal
spine model and the authors’ failure “to present any credible evidence for the validity, clinical utility and appropriateness for using
these procedures.” Haas and colleagues469 conclude that there is
currently no justification for the routine use of radiographic spinal
displacement analysis in clinical practice.
77
51,506-510
�
studies.
The principal attraction of functional x-ray examinations is the ability to assess joint mobility and identify disturbances in function that might not be represented by static films.
Functional x-ray studies involve the evaluation of regional and segmental spinal movements by comparing range and pattern of movement at each segmental level. A series of three views are typically
taken for each plane of movement evaluated: an end-range view
in each direction and a neutral view. These views are then used to
measure and evaluate restricted or aberrant segmental movements.
Although the use of dynamic x-ray examinations overcomes
concerns about the inability to functionally assess the spine with
static x-ray examinations, there remains considerable controversy
as to their contribution in predicting back pain or differentiating
those individuals with back pain from those without. Methods for
measuring and classifying segmental motion abnormalities in the
lumbar spine and cervical spine are in common use.51,164,506–508,511–513
Taylor478 suggests that functional radiography should be used to
establish the presence of the following:
1. Segmental or global hypomobility
2. Segmental or global hypermobility
3. Segmental instability
4. Aberrant segmental or global motion
5. Paradoxical motion
6. Postsurgical arthrodesis
Flexion-Extension Radiographs. Those investigating the relationship between spinal pathologic conditions and segmental
movement have demonstrated supportive evidence for the use
of flexion-extension studies in the detection of spinal instability.167,478,506,514 Flexion-extension studies are used to identify excessive angular or translational movements between spinal segments
(Figure 3-32).478,515,516 The amount of translation or angular movement necessary to define instability is not definitively established.
Most references classify any flexion-to-extension translation
greater than 3 to 5 mm as indicative of instability.478 Dvorak and
colleagues517 suggest that applying global overpressure at the end
ROM during a functional x-ray examination may aid in identifying translational movement characteristics of instability.
Clinical validity studies have been done for flexion-extension
radiographs of the lumbar and cervical spine.518,519 The conclusions were that the functional studies did show a tendency for the
presence of hypomobility in patients with clinical problems, but
they were not sufficient to aid in differentiating the underlying
pathologic conditions.
In the cervical spine, flexion-extension studies are used most
commonly to ascertain if a traumatic injury has resulted in
Functional X-ray Examination
The potential limitations of static radiographs in determining joint dysfunction has led to increased use of functional x-ray
*References 265, 335, 464, 470, 476-478, 483-486, 490, 494-503
Figure 3-32â•… Evaluation of flexion and extension radiographs in the
cervical and lumbar spine.
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| Chiropractic Technique
�
instability.
Translational movements of more than 3 mm are considered a significant finding for instability of the cervical spine. In
the cervical spine, an overlay method may be used for templating
flexion and extension (see Figure 3-32).
Lateral-Flexion Radiographs. Lateral-flexion (side-bending)
radiographs are used predominantly in the evaluation of the lumbar spine. Interpretation of the films incorporates the use of lines
and angles that are drawn on the films for the purpose of quantifying and gauging comparative quality of joint motion.
The total range of regional lateral flexion is determined by
extending a line from the superior end plate of the uppermost
vertebra and the inferior end plate (or sacral base) of the lowest
vertebra in the concavity of the curve. Perpendicular lines are constructed from each of these with the angle formed at their intersection, establishing the limit of lateral flexion (Figure 3-33).
A
B
The films can then be marked for segmental rotation and lateral flexion. The body-lamina junction is used for rotation and
the end plate angulation for lateral disc wedging. Aberrant lateral flexion can be assessed by using superior end plate lines and
evaluating if they converge toward the side of lateral bending (see
Figure 3-33).
Early investigation into the value of functional radiography did
identify its merit in the diagnosis of sciatica,520 although abnormal lumbar motion was also noted in asymptomatic patients.
Vernon509 concluded that there was a higher prevalence of abnormal lateral bending patterns in symptomatic subjects, but Phillips
et al329 and Haas and colleagues332,333 failed to demonstrate a relationship between abnormal spinal motion and patients suffering
from LBP.
Although these procedures have demonstrated limited predictive value in differentiating individuals with back pain from those
without, their value in managing patients with back pain has not
been fully assessed. Using side-bending stress x-ray studies to help
ascertain abnormalities of intersegmental motion in individuals
with back pain in theory, may affect clinical decision-making in
a manner that improves patient outcome. In this context, evaluation would be qualitative and quantitative. The detection of hypomobility, paradoxical motion (reversal of an unexpected motion
or aberrant motion), or excessive motion would have precedence
over exact measurements.
Identifying levels and directions of decreased movement might
affect decisions on where and how to make adjustments in ways
that improve patient outcome. This may be particularly applicable
in individuals with persistent pain or patients who have not been
responsive to treatment. The answers to these questions await
�further research.
Videofluoroscopy
C
D
E
Figure 3-33â•… Evaluation of functional lateral bending radiographs in
the lumbar spine demonstrating movement patterns. A, Type I, �lateral
bending with contralateral rotation. B, Type II, lateral bending with
ipsilateral rotation. C, Type III, contralateral bending with contralateral rotation. D, Type IV, contralateral bending with ipsilateral rotation. E, Segmental measurement methods for determining rotation in
millimeters and lateral flexion in degrees. (A–D from Grice A, Cassidy
D: J Manipulative Physiol Ther 2:18, 1979; E from Haas M, Nyiendo J,
Peterson C: J Manipulative Physiol Ther 13[4]:179, 1990.)
Videofluoroscopy (VF) of the spine is another radiographic
procedure that has been proposed as a potential tool for the
assessment of segmental spinal motion. Before the development of VF, cineradiography (CR) was the main radiographic
method used to evaluate spinal motion. Fielding521 first
described its use for the cervical spine, and Illi was the first
to use CR in the chiropractic profession to study spinal segmental and sectional motion. He was followed by Rich and
Goodrich in the 1960s. Howe57,522 performed numerous studies, and this procedure became an experimental procedure at a
number of institutions. The major drawback to CR was that it
involved taking 16-mm movies during which substantial radiation exposure (often exceeding 10 or 20 radiation absorbed
doses) was applied to the spine.
VF development has led to improvements in image intensifiers and digital recording technology that has resulted in far fewer
radiation doses and increased interest in recent years.523,524 VF
has the capabilities to measure the full arc of motion and therefore provides information on the quality of motion in addition
to the ROM. This allows the clinician to see aberrations in the
mid-ROM, as well as at the extremes. Advocates of VF �suggest
that these studies provide objective evidence of biomechanical
abnormalities not seen with other studies. This technology has
made significant advances, and the new techniques of digital VF
Chapter 3╅ Joint Assessment Principles and€Procedures |
(DVF) have dropped the radiation exposure rates considerably
below those of the conventional x-ray examination.525,526 When
appropriate equipment and calibration are used, the procedure has
demonstrated promising interobserver and intraobserver reliability, with measurement accuracy between 1 and 2 degrees.525-527
Although DVF holds significant promise in the assessment of
spinal mechanics, it is presently in the investigational stage, without established clinical protocols for use. It should be stressed that
spinal VF is a special test with several limitations and disadvantages (Box 3-16). Much research is necessary to precisely define
the role of VF in chiropractic.
In clinical practice, VF should be considered an experimental
procedure, and its use should be reserved for complex cases that
fail to respond, that respond poorly to a trial of conservative management, or in which suspected ligamentous damage leading to
instability has occurred. Growing concern about the inappropriate
use of VF has led to the formation of protocols for the use of VF in
chiropractic by the American Chiropractic College of Radiology,
a branch of the ACA. These protocols should be followed when
contemplating the use of VF.528
Clinical Use of X-ray Examination
The clinical utility of static and functional radiographs might
be improved if these procedures were placed in a proper clinical
perspective and considered a component of evaluation and not
a pathognomonic indicator of JSDSs. With further refinement,
they may eventually parallel a role provided by specialized imaging
techniques in the structural detection of IVD derangement.
For example, the presence of IVD derangement on a CT scan
or an MRI indicates the presence of anatomic derangement of
the IVD, but it does not confirm that the disc derangement is of
clinical significance. The incidence of radiographically detected
disc derangement in asymptomatic patients is significant (24% to
37%), suggesting that there is a poor correlation between mechanical disc derangement and morbidity.529 Within this context, it
becomes apparent that the imaging findings must be matched
to the clinical presentation and physical findings before a final
impression is established. The role of x-ray examination in the
evaluation of spinal subluxation/dysfunction syndromes (JSDS)
should play a similar purpose. Radiographic findings alone cannot
identify whether a given joint subluxation/dysfunction is clinically
relevant and worthy of treatment. They must be placed within the
context of the physical examination and patient complaints.
BOX 3-16
imitations and Disadvantages of
L
Videofluoroscopy
Expense—equipment ranges from $60,000 to $80,000.
Overuse—high costs can lead to extra ordering of tests to
offset capital outlay.
Inferior image—image definition is poor in comparison
with plain-film studies, and subtle architectural changes
are not visualized.
Justification—not enough diagnostic information is
provided to warrant the additional radiation exposure.
79
This discussion on the use and application of radiography has
been directed toward its relationship to the detection of joint subluxation/dysfunction. This is not meant to imply that chiropractors use x-ray examinations to detect joint subluxation/�dysfunction
only. They are commonly used to investigate fractures, pathologic
conditions, and biomechanical integrity.
A rational for the use of plain-film imaging in the chiropractic
office is (1) to assist in the establishment of a working diagnosis
when clinically indicated, (2) to rule out the presence of pathologic conditions that contraindicate manipulative therapy, (3) to
identify any anomalies or structural changes that may influence
how an adjustment will be made, and (4) to determine static and
functional biomechanical relationships that may have �clinical
relevance to the patient’s symptoms or health.
No one tool should be used to make clinical decisions, and
x-ray interpretation should not be an exception. The fundamental
principles in the use of radiology that are of prime importance and
that should be considered before x-ray examinations are ordered
are identified in Box 3-17.
Instrumentation
In the absence of a “gold standard” for the assessment of characteristics associated with joint subluxation/dysfunction syndrome
(JSDS), the chiropractic profession has sought an instrument that
would objectively measure and quantify its presence.
However, even if such an instrument existed, it would likely be
limited to the identification of only a single clinical characteristic
or finding. This finding may be associated with joint subluxation/
dysfunction or with other clinical entities. Therefore, no single
tool should be relied on to make the diagnosis or assessment of
subluxation/dysfunction syndrome.
The following tools represent means to identify specific characteristics potentially associated with joint subluxation/dysfunction. Although most have fair to good reliability, their validity has
not been adequately determined or tested. Moreover, some proponents of specific instruments have made inappropriate claims
about the value of the information gleaned from the instruments.
Algometry
Algometry is the measurement of pain. Algometers are force gauges
that are used to quantify the amount of pressure necessary to elicit
a painful response (Figure 3-34). Algometers are used at both
BOX 3-17
undamental Principles in the Use of
F
Radiography
Radiographs should be considered only after an appropriate
and thorough history and examination.
Radiographs should be ordered based only on clinical need.
Routine radiographic examination without clinical need is
inappropriate.
When selecting patients for radiographic study, the benefit
of the x-ray information must always outweigh the risk of
ionizing radiation to the patient’s health.
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| Chiropractic Technique
Figure 3-34â•… Algometer.
bony and soft tissue sites. Algometric measurements represent the
point of maximal pressure the patient can tolerate (pressure tolerance [PTo]) or the point at which pressure induces pain (pressure
pain threshold [PPT]).
PPT is alternatively referred to as the first verbal report of pain.
PTo is alternatively referred to as the pain reaction point (PRP),
the point at which the patient reports that it “hurts a lot.” PPT
measurements are more commonly used because they are less
intrusive.
To evaluate the patient’s PPT, the examiner places the rubbertipped stylus of the algometer over the site to be evaluated and
applies steady, gentle pressure at a rate of approximately 1 kg/sec.
Pressure is applied until the patient feels pain and responds by saying “now.” At this point the stylus is removed, and tender sites and
their pressure values are recorded.
Normative PPT values for muscle and bone have been established, and repeated measures have demonstrated good reliability.530-536 Algometry is presented as an effective tool for evaluating
painful musculoskeletal complaints.537 It has demonstrated reliable measurement of pain in temporomandibular joint dysfunction,536,538 myofascial trigger point syndromes,534 muscle tension
headache,539 and the ability to differentiate patients with inflammatory arthritis from healthy controls.540 Algometry is responsive
to treatment, effectively documenting increased PTos in disorders treated with adjustive therapy.541,542 Algometry has been used
most commonly in research settings, but its ease of use, low-tech
application, and affordability make it appropriate for use in clinical practice.
Thermography
Medical thermography is the technique of measuring and recording heat emission from the body. The body radiates heat in a symmetric pattern, with only minor variation in temperature from side
to side. In a healthy individual, temperature radiation is regionally
symmetric to within 0.5 to 1 degree centigrade.543,544
The most common devices used to assess human heat emission
are electronic infrared and liquid crystal appliances. Significant
asymmetry in heat emission has been postulated as objective
evidence of a variety of underlying disorders and painful complaints. In manual medicine, thermography is most frequently
discussed as a noninvasive means to detect functional changes
that may be associated with disorders of the NMS system.
Figure 3-35â•… Thermocouple device used to evaluate paraspinal temperature symmetry.
Christiansen,545 in a review of the literature, found thermography compared favorably with other diagnostic tests (e.g.,
myelography, EMG, and CT) for accuracy and sensitivity in
determining the level of radiculopathy while demonstrating
high correlation with these more invasive tests.546 A hand-held
device that uses either infrared contact thermistors or thermocouples may be used. This device is used to detect regional variations in midline spinal temperature or variations in segmental
paraspinal temperature. The temperature differential is usually
displayed on a calibrated galvanometer or plotted on a strip
graph.
The thermocouple device is constructed to make physical
contact with the surface of the body and measure differences
in segmental paraspinal temperature (Figure 3-35). Deflection
of the needle will be to the relatively warmer side. Alteration in
�segmental temperature is speculated to represent objective evidence of spinal subluxation/dysfunction syndromes. It is postulated that spinal subluxation/dysfunction may produce a local
inflammatory reaction or reflex alteration in sympathetic tone,
which in turn alters the segmental temperature symmetry of the
body.547-551
Although some techniques advocate using hand-held heat
detection instruments for spinal subluxation/dysfunction detection, very little research has been conducted on the reliability or
validity of these devices. Normative values for hand-held devices
have not been established, and reliability studies are very limited.
To date, no studies have been conducted to evaluate their validity
in determining spinal dysfunction.552 Further research is needed
to confirm or refute the theories, indications, and limitations of
these devices.553
Galvanic Skin Resistance
Galvanic skin resistance (GSR) is the measure of the skin’s electrical conductivity. Galvanic skin instruments measure the resistance of
the skin to a small electrical current. It has been suggested that spinal
dysfunction may alter skin conduction by inducing sympathetically
mediated changes in sweat gland secretion (somatovisceral reflex).554
Chapter 3╅ Joint Assessment Principles and€Procedures |
Conductivity of the skin is significantly affected by its moisture content and sweat gland activity.555
Spinal dysfunction is hypothesized to alter conduction by
either increasing or decreasing sweat gland activity. Spinal dysfunction that leads to increased peripheral autonomic activity
and sweat gland secretion could increase segmental conductance.
Spinal dysfunction that leads to inhibitory autonomic activity could result in a decrease in skin conductance. The presence
of pain has also been shown to induce a segmental decrease in
GSR.556,557
Ease of access to the skin makes GSR an uncomplicated tool
for measuring autonomic effects that may be associated with
�spinal dysfunction. GSR has been used in experimental settings
on a very limited basis. Its clinical value remains to be evaluated,
and it is seldom, if ever, used in the day-to-day clinical evaluation
of joint dysfunction.
Surface Electromyography
A method purported to assess a specific characteristic of spinal
dysfunction is paraspinal EMG scanning. Paraspinal muscle dysfunction is considered a clinical manifestation of joint subluxation/dysfunction syndrome, and surface EMG is presented as a
method that can provide an objective quantitative evaluation of
changes in paraspinal muscle function.
EMG is a technique for recording electrical potentials associated with muscular activity. This is considered important to
�clinicians because it represents the outflow of motor neurons in
the spinal cord to the muscle as a result of voluntary or reflex
activation.558 Either needle electrodes or surface electrodes can
be used to study paraspinal or peripheral muscle function.
However, needle electrode and surface electrode EMGs are not
interchangeable procedures.559 Needle electrode techniques are
indicated for the evaluation of specific muscles, �innervation
potentials, and myopathies. Surface electrode techniques are
indicated for kinesiologic studies of the global function of
groups of muscles.
The muscle activity that is recorded by the various paraspinal scanning machines are relative values, relating to resting and
�contractile muscle states. Muscle unit action potentials are amplified by the EMG machine. The responses are filtered and rectified by the instrument. These rectified responses are bidirectional
waves of depolarization and repolarization along cell membranes.
They are integrated over time, and analog signals are converted to
digital signals.
Surface electrode EMG with attached electrodes has been
shown to exhibit very good to excellent test-retest reliability.560-565
In a comprehensive review article comparing the properties of
fixed-surface electrode EMG and intramuscular EMG, Turker558
identified that both procedures have indicated uses. Surface electrode EMG was found to be more prone to electrical artifacts,
mechanical artifacts, and contamination from the activity of
other muscles than intramuscular EMG. However, it is possible
to make useful recordings with the surface electrode from large
superficial muscles if appropriate precautions are observed.
In a comparison study using needle electrode and fixed-surface
electrode EMG, evaluated muscles were electrically silent, during standing and full flexion. The use of fixed-surface electrodes
81
�
provided
recordings that were similar, although slightly dampened, to those obtained with intramuscular wire electrodes.566 The
surface measurements were found to accurately document the
function of back muscles, permitting the use of fixed-surface electrode EMG in outpatient care. Furthermore, fixed-surface EMG
has been shown to provide a very valuable set of data used diagnostically with pain-related disorders.567
Scanning-surface EMG should not be confused with surface EMG that uses fixed-surface electrodes. Electromyographic
muscle scanning measures 2-second samples of integrated muscle action potentials from individual neck and back muscles
using a hand-held scanner with post-style surface electrodes
separated by a fixed distance. This scanning technique is used to
expeditiously assess muscle activity in the diagnosis of musculoskeletal disorders.564,568 The signal recorded by the apparatus
is a transient signal. There are a number of potential technical
problems with this equipment, including low signal or noise
ratios; movement signal artifacts (because the surface electrodes
are not fixed to the skin); and other sources of signal artifacts,
such as those from the heart and great vessels. Surface-scanning
paraspinal EMG gives a rough estimation of transient muscle activity. It cannot give information about specific muscles
because the recording electrodes are placed over the skin and
not into a muscle.
Thompson and colleagues564 report that their study supports hand-held post-style electrodes as providing a satisfactorily
stable means of monitoring the surface EMG signal. However,
they also identify that the 2-second integration period may be
inadequate, favoring instead a 10-second integration, especially
in research and treatment outcome studies. When attention is
directed to scan preparation, hand-held EMG sensors produce
dependable results. The reliability of the surface EMG scanning procedure was investigated using a large clinical �sample;
the results indicated that with adequate attention to scan preparation, EMG sensors held in place by hand with light pressure
produced dependable results. The pattern of reliability was seen
to be slightly higher in the lower back on patients in the standing position.569
Questions regarding surface electrode EMG’s validity and
usefulness exist, yet its use is often embraced by many without
reserve.570 Lehman conducted three experimental studies to evaluate surface electrode EMG for asymmetry and repeatability in populations with LBP and populations without LBP. He concluded
that EMG signals during quiet stance show excellent repeatability but segmental differences in asymmetry between problematic
and nonproblematic segments were not evident. This suggests that
the diagnostic validity of EMG evaluations during simple quietstance tasks is highly suspect. Ritvanen et al571 also found no positive nor statistically significant association between back pain and
EMG parameters.
Surface-electrode EMG has the potential to assist the doctor
in evaluating the patient’s response to treatments.559 Myerowitz,572
using hand-held scanning electrodes, evaluated the relationship between post-treatment paraspinal surface EMG improvement and improvements in spinal pain or related musculoskeletal
symptoms. He treated 42 symptomatic patients with pain and
abnormal scanning surface EMG findings. All 42 patients had
82
| Chiropractic Technique
post-treatment improvement on scanning-surface EMG readings,
and 41 patients (97.6%) reported post-treatment reduction in the
pain symptoms. This study raises the possibility of using handheld scanning surface EMG to correlate EMG activity to symptomatic improvement in common conditions of spinal pain and
related musculoskeletal symptoms.
Although scanning-surface EMG has generated some enthusiasm in the profession, the use of scanning surface paraspinal
EMG for the detection of spinal subluxation syndromes must
be questioned.573 The profession, in attempting to document
intersegmental dysfunction, has jumped too quickly onto an
unproven application.574 Aside from the potential hardware
problems presented, chiropractors must question the need for
the routine use of an examination procedure that tells the doctor
there is some local muscle tone alterations. Chiropractic doctors
have sufficient training and palpation skills to assess contracted
muscles, and the cost generated by this technology may not be
warranted.
Scanning-surface EMG may have potential value as an
outcome measure, but its validity in detecting joint subluxation syndromes has not been substantiated. The important
clinical questions remain unanswered. Instruments, including
scanning-surface EMG, must be evaluated within a clinical
context. The interpretation of information derived from these
instruments and how it affects clinical decisions and treatment
is the determining factor in establishing its validity and clinical utility.575
1
2
3
4
5
6
Pain
7
1
2
Trigger point
3
Prominent landmark
4
5
Painful joint play
6
Reduced joint play
7
8
9
Increased joint play
10
11
12
1
2
Spinous deviation left
3
4
5
Muscle spasm
Spinous deviation right
Deep thickening (ropey feel)
Presence of symbol indicates mild;
+ after symbol indicates moderate;
++ after symbol indicates marked
or severe.
CLINICAL DOCUMENTATION
Practice efficiency is enhanced when manual examination
findings are recorded with symbols on charts. One of the less
rewarding aspects of practice is the time spent writing reports.
Accurate and legible chart notes make that process more efficient and less tedious. A method that is quick and accurate can
take the drudgery out of note-taking and free the doctor to concentrate on patient care. Figure 3-36 outlines a set of symbols
used to record the location of pain and other bony and soft
tissue abnormalities. Figure 3-37 contains examples of methods that can be used to record abnormalities in ROM, JP, and
EP. There are many different methods, and each doctor usually makes modifications to fit his or her style. These examples
are offered in the hope that they will be of value in the search
and development of a method of charting. The total management of the patient includes clinical assessment, application of
�necessary treatment, and patient education. Clinical assessment
procedures are performed to identify appropriate case management—frank acceptance and sole responsibility for care, acceptance with consultation from other health care professionals,
and frank referral transferring responsibility for immediate care
to another health care professional. Assessment procedures are
necessary to identify the nature, extent, and location of the
problem, as well as to determine the course of action in treatment. Last, these same procedures must be used to monitor the
effects of care. It is an important process to record adequately
the various aspects of care.
Figure 3-36â•… Examples of symbols and recording method for charting
and tracking joint assessment findings.
Errors in recording that have been identified include failure to record findings altogether, illegible handwriting, obscure
�abbreviations, improper terminology, and bad grammar. It is
imperative that although the clinical record comprises the doctor’s
personal notations, it must be complete and translatable. If it is
not written down, it was not done.
A systematic and accurate record of evaluation facilitates quick
reference to salient findings during treatment. When findings
either modify or contraindicate some aspect of treatment, this
should be noted in a conspicuous location on the patient’s record
so that it is readily seen before each visit.
It should be noted and emphasized that it is unacceptable to
use and assign a diagnosis for convenience. Most clinical entities
have specific and expected signs and symptoms. These findings
need to be identified and recorded. Although it is nearly impossible to have complete certainty as to the nature and extent of the
clinical problem, the compilation of clinical findings is necessary
to influence the clinical judgment used in applying interventions
in patient care. Furthermore, it must be clearly understood that
third-party payers reimburse for problems (they provide “disease”
insurance, not “health” insurance). The reporting of Â�problems to
Chapter 3╅ Joint Assessment Principles and€Procedures |
Flexion
Left rotation
Right rotation
Left lateral
flexion
Right lateral
flexion
Motion restriction
Extension
TABLE 3-5
ICD Codes for Subluxation
Version 9
Version 10
739
Nonallopathic lesions including
segmental dysfunction
M99.ØØ
Head region
M99.Ø1
Cervical region
M99.Ø2
Thoracic region
M99.Ø3
Lumbar region
M99.Ø4
Sacral region
M99.Ø5
Pelvic region
M99.Ø6
Lower extremities
M99.Ø7
Upper extremities
M99.Ø8
Rib cage
739.0
739.1
739.2
739.3
739.4
739.5
739.6
739.7
739.8
839
C3–C4
839.00
Mild restriction
EP
P
839.01–07
EP
Moderate restriction
Marked restriction
P
PM EP
Painful movement
839.21
839.20
839.41
839.42
83
Multiple, ill-defined dislocations, closed
dislocation
M99.11
Cervical spine, vertebra
unspecified
S13.11ØA- Cervical spine, vertebra
17ØA
specified
M99.12
Thoracic vertebra
M99.13
Lumbar vertebra
S33.2XXA
Coccyx
M99.14
Sacrum
PM Passive range
EP End-play range
Figure 3-37â•… Diagram for recording segmental motion palpation
findings.
third-party payers must be substantiated in the clinical record.
When subluxation/dysfunction syndrome is the primary or
reportable component of the diagnosis, an ICD-9CM code can
be used. Table 3-5 identifies the codes used to report subluxation/
dysfunction syndrome.
Principles of Adjustive Technique
OUTLINE
CLASSIFICATION AND DEFINITION
OF€MANUAL THERAPIES
84
JOINT MANIPULATIVE
PROCEDURES
84
Adjustment
84
Manipulation
88
Joint Mobilization
88
Manual Traction-Distraction
88
SOFT TISSUE MANIPULATIVE
PROCEDURES
88
INDICATIONS FOR ADJUSTIVE
THERAPY
89
MECHANICAL SPINE PAIN
89
JOINT SUBLUXATION/DYSFUNCTION
SYNDROMES╇ 90
Clinical Findings Supportive of
Joint Subluxation/Dysfunction
Syndrome╇ 90
CONTRAINDICATIONS TO AND
COMPLICATIONS OF
ADJUSTIVE THERAPY╇ 92
Cervical Spine╇ 94
Thoracic Spine
102
Lumbar Spine
103
EFFECTS OF ADJUSTIVE THERAPY 105
Musculoskeletal
105
Non-musculoskeletal
106
C
hiropractors must maintain the necessary diagnostic skills
to support their roles as primary contact providers. There is,
however, a wide range of choice in the chiropractor’s scope
of practice. Therapeutic alternatives range from manual therapy
and spinal adjustments to physiologic therapeutics and exercise,
nutritional and dietary counseling.1,2
Although there is great variation in scope of practice from state
to state, nearly all chiropractors use a variety of manual therapies
with an emphasis on specific adjustive techniques.1,3-8 The preceding
chapters focused on the knowledge, principles, examination procedures, and clinical indications for applying adjustive therapy. This
chapter focuses on the knowledge, mechanical principles, and psychomotor skills necessary to effectively apply adjustive treatments.
CLASSIFICATION AND DEFINITION OF
MANUAL THERAPIES
Manual therapy includes all procedures that use the hands to mobilize, adjust, manipulate, create traction, or massage the somatic or
visceral structures of the body.9 They may be broadly classified as
those procedures directed primarily at the body’s joint structures
or soft tissue components (Figure 4-1).
JOINT MANIPULATIVE PROCEDURES
Joint manipulative therapies are manual therapies, the primary
effect of which is on joint soft tissue structures (Box 4-1). They
are physical maneuvers designed to induce joint motion through
either nonthrust techniques (mobilization) or thrust techniques
(adjustment or thrust manipulation). They are intended to treat
disorders of the neuromusculoskeletal (NMS) system by decreasing pain and improving joint range and quality of motion. This
leads to their common application in the treatment of NMS
disorders that are associated with joint pain or joint hypomobility
(subluxation/dysfunction).
84
Chapter
4
Mechanical Hypotheses
Joint Fixation
Neurobiologic Hypothesis
Circulatory Hypothesis
APPLICATION OF ADJUSTIVE
THERAPY
Joint Anatomy, Arthrokinematics,
and Adjustive Movements
Adjustive Localization
Adjustive Psychomotor Skills
Motion-Assisted Thrust
Techniques
106
112
115
120
120
121
123
128
142
When joint dysfunction/subluxation syndrome (hypomobility or malposition) is treated, the adjustive thrust or mobilization
is typically delivered in the direction of reduced joint motion to
restore normal motion and alignment. For example, if the lumbar spine has a restriction in right rotation, the doctor thrusts
to induce more right rotation in the affected region. In some
instances, the therapeutic force may be delivered in the relatively
nonrestricted and pain-relieving direction. This is most common
when acute joint pain and locking limit movement in one direction, but still allow distraction of the joint capsule in another
direction.10-12 Under these circumstances, therapy is most commonly directed at inducing separation of joint surfaces. The goal
is to inhibit pain and muscle guarding and to promote flexible
healing.
Adjustment
Adjustments are the most commonly applied chiropractic
therapy.3-5 They are perceived as central to the practice of chiropractic and the most specialized and distinct therapy used by
chiropractors.3,4,13 Specific reference to adjustive therapy is incorporated in the majority of state practice acts, and it is commonly
cited as a key distinguishing feature of chiropractic practice.14
Although adjustive therapy is central to most chiropractic practices, the authors do not want to impart the impression that chiropractors should limit their clinical care to adjustive treatments.
Patient management and treatment plans should be based on the
best available evidence, clinical judgment, and patient preferences.
There are circumstances in which the best standard of care for
a given NMS disorder involves the application of nonadjustive
treatments singularly or in combination with adjustive therapy.
Other therapies commonly applied by chiropractors include joint
mobilization and light-thrust techniques; soft tissue massage and
manipulation; physical therapy modalities; and instruction on
exercise, ergonomics, lifestyle, and nutrition.
Chapter 4â•… Principles of Adjustive Technique |
Box 4-1
Manual Therapy Terminology
Manual Therapy
Procedures by which the hands directly contact the body to
treat the articulations or soft tissues.16
Joint Manipulation
(1) Joint manipulative therapy broadly defined includes all
procedures in which the hands are used to mobilize, adjust,
manipulate, apply traction, stimulate, or otherwise influence
the joints of the body with the aim of influencing the patient’s
health; (2) a manual procedure that involves a directed thrust to
move a joint past the physiologic ROM without exceeding the
anatomic limit;16 (3) skillful or dexterous treatment by the hand.
In physical therapy, the forceful passive movement of a joint
beyond its active limit of motion.
Adjustment
(1) A specific form of joint manipulation using either long- or
short-leverage techniques with specific anatomic contacts. It
is characterized by a low-amplitude dynamic thrust of controlled velocity, amplitude, and direction. Adjustments are
commonly associated with an audible articular crack (cavitation). (2) any chiropractic therapeutic procedure that uses
controlled force, leverage, direction, amplitude, and velocity, which is directed at specific joints or anatomic regions.
Chiropractors commonly use such procedures to influence
joint and neurophysiologic function.16
CLASSIFICATION OF MANUAL THERAPIES
Joint manipulation
procedures
Mobilization
85
Adjustments
Manual traction
distraction
Soft tissue manipulation
procedures
Point pressure
techniques
Visceral
manipulation
Massage Therapeutic
muscle
stretching
Figure 4-1â•… Classification of manipulative procedures. (This illustration is not intended to cover all possible manual therapies.)
Unfortunately, the common use of adjustments by chiropractors has not led to a clear and common understanding of the
defining characteristics of an adjustment.14,15 A mid-1990s consensus process made major strides in reaching consensus on many
of the chiropractic profession’s unique terms.19 However, several
key terms within this document lack clarity. At issue is whether
the definitions presented for adjustment and manipulation are clear
and distinct or so broad that they have limited descriptive value.
Historically, adjustive therapy was defined primarily in the context of the doctor’s therapeutic intentions. If the doctor applied a
Direct (Short-Lever)
Specific joint contact; high velocity–low amplitude thrust.
Semidirect
Combination of specific joint contact and distant long-lever
contact; high velocity–low amplitude thrust.
Indirect (Long-Lever)
Nonspecific contact established at leverage points distant to
affected joint.
Joint Mobilization
(1) Form of nonthrust joint manipulation typically applied within
the physiologic range of joint motion. Mobilizations are passive
rhythmic graded movements of controlled depth and rate. They
may be applied with fast or slow repetitions and various depth.
Although joint mobilization is not commonly associated with
joint cavitation, deep mobilization (grade 5) may induce cavitation; (2) movement applied singularly or repetitively within
or at the physiologic range of joint motion, without imparting
a thrust or impulse, with the goal of restoring joint mobility;16
(3) manual traction-distraction: a form of mobilization producing a tractional or separating force. It may be accomplished
manually or with mechanical assistance and can be sustained
or intermittent.
treatment procedure with the intention of reducing a joint subluxation, it was considered an adjustment.17,18 Based on this premise,
any procedure delivered by a chiropractor and directed at reducing joint subluxation could be considered an adjustment. This
approach results in a wide variety of significantly different physical procedures all being classified as adjustments.
The 1990s consensus process appropriately moved the focus
away from defining adjustments based on therapeutic intention
and toward defining an adjustment based on its physical characteristics. However, the definition maintained a very broad and
inclusive approach. Adjustments were defined “as any chiropractic therapeutic procedure that utilizes controlled force, leverage,
direction, amplitude and velocity.”19 The definition did not limit
the application of adjustments to the joints of the body, but specified that adjustments could be delivered to any anatomic region
(see Box 4-1, Adjustment 2). In this context, it is difficult to perceive a chiropractically applied procedure that would not be classifiable as an adjustment. A wide variety of diverse procedures
(thrust and nonthrust joint manipulation, adjustment, massage,
manual or motorized traction, etc.) all involve force, leverage,
direction, amplitude, and velocity. More than 100 different named
technique systems have been identified within the chiropractic
profession, and most of them call their treatment procedure an
adjustment (see Appendix 1).20 A number of these procedures do
not share discrete physical attributes and may not be equivalent
in their physical effects and outcomes. The profession needs to
86
| Chiropractic Technique
objectively evaluate and compare the effectiveness of chiropractic therapeutic procedures. This cannot be accomplished without
physically distinct classifications of commonly employed manual
therapies. Until this issue is addressed, it will be difficult for the
profession to determine which therapies are most effective and in
what clinical conditions.
The basis for distinguishing and classifying adjustive procedures should incorporate their measurable characteristics and
should not be based solely on therapeutic intention. Separating the
physical components of an adjustment from the rationale for its
application does not diminish it significance. As stated by Levine,
“It is the reason why techniques are applied and why they are
applied in a certain manner that distinguishes chiropractic from
other healing disciplines.”21
The historically broad perspective on and definitions of what
constitutes an adjustment have led to a wide variety of procedures being classified as adjustive methods. The assumption that all
forms of adjustment, as presently defined, are equivalent must be
avoided.22 As discussed previously, many in the profession do not
equate an adjustment with a thrust, and a number of chiropractic technique systems do not incorporate thrust procedures.19 In
addition to differences that may exist in the form of applied treatment, many technique systems attempt to distinguish themselves
not by the attributes of the adjustment they perform, but rather
by what they claim to be their unique underlying biomechanical
and physiologic principles and rationale.
Despite the variety of procedures that have been labeled as
adjustments, most share the common characteristic of applying
a thrust. It is this attribute that we propose as the central defining and distinguishing physical feature of the chiropractic adjustment.9,23,24 Although amplitude and velocity of the adjustive
thrust may vary, it is a high velocity–low amplitude (HVLA) ballistic force of controlled velocity, depth, and direction. With this
in mind, we suggest the following definition: The adjustment is a
specific form of direct articular manipulation, using either longor short-leverage techniques with specific contacts characterized
by a dynamic thrust of controlled velocity, amplitude, and direction (see Box 4-1, adjustment 1). Adjustive contacts are usually
established close to the joint being treated, and the thrust is delivered within the limits of anatomic joint integrity. Adjustive therapy is commonly associated with an audible articular “crack,” but
the presence or absence of joint cracking should not be the test for
determining whether or not an adjustment has been performed.
Properly applied adjustments are commonly painless, although
the patient may experience some momentary, minimal discomfort. A short-duration mild increase in local soreness after manipulation has been reported in up to 50% of patients treated with
manipulation and should not be considered an inappropriate
response.25 Adjustments should not be forced when preloading a
joint in the direction of intended manipulation induces pain or
protective patient guarding and resistance. Adjustive procedures
that induce discomfort during application should be considered
only if they are directed at increasing joint mobility.
Categorization of Adjustive Procedures
Various proposals have been made to further subclassify adjustive thrust procedures. However, most classification schemes
suffer from the central problem of beginning with an unworkably broad definition of adjustment. This creates an unnecessary burden on authors who then try to subclassify adjustments
by the very attributes that are commonly used to distinguish
adjustments from other forms of manual treatment. One common approach is to distinguish adjustments by the degree of
applied velocity. It is not uncommon to see references in the
chiropractic literature and trade magazines in which different
methods are presented and promoted as low-force or nonforce
methods. This carries an inference that these procedures are different from other adjustive techniques and are associated with
less peak force. These descriptions commonly do not explain if
the procedures are applied with a thrust, nor do they explain
how much actual force is involved or how they truly compare
with other adjustive procedures. Furthermore, measurements
of adjustive preload, peak force, and amplitude appear to vary
within the same adjustive methods. When the same adjustive
methods are applied at different anatomic regions or on different
patients, the preload, rate of velocity, and peak velocity change
significantly.26 These noted differences are no doubt the product of each doctor’s trained ability to note and modify his or her
adjustive procedures relative to the encountered joint resistance
of each spinal region and patient, rather than a conscious effort
to use a different adjustive procedure. It is doubtful that any
meaningful distinction can be achieved by trying to subclassify
adjustments by moderate differences in applied velocity. How
would the velocity be measured in day-to-day practice, and how
much of a change would be necessary to distinguish one method
from the other? Nothing is gained by redefining a joint mobilization as a low-velocity, moderate-amplitude adjustment simply
because it is performed by a chiropractor.
In an attempt to be more precise in the distinction, classification, and validation of chiropractic procedures, Bartol15,27 and
the Panel of Advisors to the American Chiropractic Association
Technique Council proposed an algorithm for the categorization of chiropractic treatment procedures. This scheme
includes criteria for velocity, amplitude, and the use of manual
or mechanical devices to deliver the adjustment. These models
were presented at the Sixth Annual Conference on Research and
Education and are commendable attempts to further distinguish
adjustive methods.28 However, they too lack any clear criteria
for distinguishing various levels of high- and low-velocity or
high- and low-amplitude adjustments. The criteria for distinguishing manual from mechanical methods are valuable and
easily discernible, but they leave a number of other important
qualities and potential distinguishing features unaddressed. The
criteria include patient positioning (PP), contact points (CPs),
leverage, and type of thrust.
To distinguish one adjustive procedure from the other, we suggest a system that begins with the assumption that adjustments
are HVLA thrust procedures, which can be further differentiated
and subcategorized by the components listed in Box 4-2. The suggested method incorporates elements used by the National Board
of Chiropractic Examiners on Part IV of the Practical Adjustive
Examination and avoids the dilemma and technological difficulties encountered in trying to differentiate adjustments by minor
changes in velocity and depth of thrust.
Chapter 4â•… Principles of Adjustive Technique |
SPECIFIC VERSUS GENERAL SPINAL
ADJUSTMENTS
Specific adjustments involve procedures used to focus the adjustive force as much as possible to one articulation or joint complex.
Specific adjustments typically involve the application of shortlever contacts (Figure 4-2). Specificity is assumed to result from
establishing adjustive contacts over or near the targeted joint with
precise attention given to adjustive vectors. General adjustments
involve procedures that are assumed to have broader sectional contacts and effects, mobilizing more than one joint at a time. They
are applied when a regional distraction of a group of articulations
is desired and commonly involve longer levers and multiple contact sites (see Figure 4-2). Nwuga29 used the term nonspecific in
this manner and stated that most of the techniques described by
Cyriax30 would fall into this category. Grieve31 uses the terms localized and regional to distinguish between procedures that affect a
single joint or a sectional area. Also, the term general has been used
Box 4-2
Categorization of Adjustive Methods
Manual vs. nonmanual
Motion-assisted vs.
non–motion-assisted
Anatomic region
Direct, indirect, or
semidirect
Patient position
Prone
Supine
Side-posture
Sitting
Standing
Knee-chest
A
Contact point (doctor’s anatomic
contact on patient)
Segmental contact point (anatomic
location of contact on patient)
Assisted (superior vertebral
contact of involved motion
segment)
Resisted (inferior vertebral
contact of involved motion
segment)
Thrust
Push
Pull
Counterthrust (push-pull)
87
to denote the nonspecific, regional, or sectional forms of manipulation.32 Therefore techniques considered to be nonspecific
use broad and long-lever contacts taken over multiple sites with
the purpose of improving motion or alignment in an area that is
generally stiff or distorted. Grice and Vernon33 suggest that this
type of procedure is indicated to free general fixations or reduce
general muscle spasms, such as those seen in spinal curvatures.
The chiropractic profession has emphasized short-lever procedures, theorizing that these are more precise in correcting local
subluxation/dysfunction without inducing stress or possible injury
to adjacent articulations. This may be especially pertinent in circumstances with adjacent joint instability. Recent research investigating some of the biomechanical assumptions of the specificity
paradigm has raised some significant challenges to this model.34,35
This research does not diminish the demonstrated clinical effectiveness of adjustive therapy,36,37,38 but it does bring into question
whether precise joint specificity is achievable or essential for adjustive therapy to be clinically effective.34 Further discussion of this
topic is presented later in this chapter under the application of
adjustive therapy section.
CHIROPRACTIC TECHNIQUE
Technique refers to a method for accomplishing a desired aim. In
chiropractic, the term is generally applied to manual therapeutic procedures directed at treating joint subluxation/dysfunction.
Although it is most frequently applied to manual adjustive procedures, it is not unusual to see the term applied to other forms of
chiropractic manual and nonmanual therapy.
Many chiropractic diagnostic and therapeutic procedures
(techniques) have been developed empirically in the profession
by an individual or association of individuals. These techniques
are commonly then assembled as a system, incorporating theoretic
models of joint dysfunction with procedures of assessment and
treatment. Appendix 1 is a list of system techniques.
Chiropractic technique should not be confused with chiropractic therapy or treatment, which includes the application of
B
Figure 4-2â•… A, Prone short-lever thoracic adjustment applied to induce segmental rotation. B, Side-posture long-lever adjustment applied to induce
segmental or sectional rotation.
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| Chiropractic Technique
the entire range of primary and ancillary procedures indicated in
the management of a given health disorder. These are limited by
individual state statutes, but may include such procedures as joint
mobilization, therapeutic muscle stretching, soft tissue manipulation, sustained and intermittent traction, meridian therapy, physical therapy modalities, application of heat or cold, dietary and
nutritional counseling, therapeutic and rehabilitative exercises,
and biofeedback and stress management.
Manipulation
In contrast to the broad definition of adjustment, the 1990s consensus project defined joint manipulation in more narrow terms
and limited its application to joint-thrust procedures (see Box 4-1,
joint manipulation 2).16 This is not uncommon, and it is becoming the norm. However, joint manipulation is also commonly used
in a broader context (see Figure 4-1 and Box 4-1, adjustment 1). In
this context, manipulate means to skillfully use the hands to move,
rearrange, and alter objects. When applied to manual therapy and
biologic tissue, it has not historically been limited to high-velocity
thrust procedures. It frequently had a broader application, which
encompassed a number of more specific procedures applied to soft
tissues and joints, such as soft tissue manipulation, massage, and
joint mobilization (see Box 4-1).
It is not likely that the world of manual therapy will limit use
of the word manipulation to thrust procedures. Joint manipulation will likely continue to be used in both its broad and narrow
contexts. This potentially confusing state could be remedied if the
term joint thrust manipulation was substituted for joint manipulation whenever it is associated with a high-velocity thrust. In the
absence of such a convention, the reader must ascertain from the
context which specific application is being used. HVLA is being
used more commonly in the literature to facilitate a clearer description when thrust manipulation is being referenced.
Joint Mobilization
Joint mobilization in contrast to adjustive therapy does not use
a thrust.9,39 Joint mobilization is applied to induce movement
through a series of graded movements of controlled depth and
rate without a sudden increase in velocity. It is a common mistake to consider mobilization as a procedure that cannot induce
movement into the end range of the elastic zone (paraphysiologic
space). Deep joint mobilization may be associated with an audible crack (cavitation). Joint cavitations do not occur as frequently
with mobilization as they do with thrust procedures, but the presence or absence of joint cavitation during the procedure does not
distinguish a mobilization from an adjustment or thrust manipulation. Joint mobilization procedures are detailed in Chapter 7.
Manual Traction-Distraction
Manual traction-distraction is another form of manual therapy
used to mobilize articular tissues. Traction is not a unique and separate form of treatment, but is simply one form of passive mobilization.40 Therefore, the distinction between joint mobilization and
manual traction-distraction is not clear, and the separation may be
arbitrary. When the technique is applied to articular tissues,
the goal is to develop sustained or intermittent separation of joint
surfaces. In the field of manual therapy, traction-distraction is
performed through contacts developed by the clinician and is
often aided by mechanized devices or tables.
Traction techniques are thought to aid in the application of an
adjustment by first allowing physiologic rest to the area, relieving compression that results from weight bearing (axial loading),
applying an imbibing action to the synovial joints and discs, and
opening the intervertebral foramina. Many of these procedures are
also quite useful for elderly patients when an HVLA thrust may be
contraindicated. Moreover, traction maneuvers produce long-axis
distraction in the joint to which they are applied. There is a longaxis distraction movement of joint play (JP) at every synovial joint
in the body.41 Yet in the spine, the fact that this important joint
movement is necessary for normal function of the joint is mostly
ignored or forgotten. Perhaps this is because testing for long-axis
distraction of the spinal joints can be difficult to elicit manually.
The term traction refers to the process of pulling one body in
relationship to another, which results in separation of the two
bodies.42 Traction is a passive translational movement of a joint
that occurs at right angles to the plane of the joint, resulting in
separation of the joint surfaces. Kaltenborn42 divides manual
traction into three grades of movement. In the first, there is no
appreciable joint separation, because only enough traction force is
applied to nullify the compressive forces acting on the joint. The
compressive forces are a result of muscle tension, cohesive forces
between articular surfaces, and atmospheric pressure. The second
effect produces a tightening in the tissue surrounding the joint
that is described as “taking up the slack.” The third grade of traction requires more tractive force that produces a stretching effect
into the tissues crossing the joint. The principal aim of treatment
is restoration of normal, painless range of motion (ROM).
Traction can be applied manually or mechanically, statically
or rhythmically, with a fast or slow rate of application. The force
applied may be strong or gentle and applied symmetrically or
asymmetrically. The effects of traction are not necessarily localized,
but may be made more specific by careful positioning. Although
traction has focused mostly on the lumbar and cervical spine
regions, there are descriptions for the application of rhythmic
traction to all regions of the spine and extremities. Furthermore, the
indications for traction include changes that are common to most
synovial joints in the body. Chapter 7 provides detailed descriptions
of traction techniques.
SOFT TISSUE MANIPULATIVE PROCEDURES
Soft tissue manipulative procedures (Box 4-3) are physical procedures using the application of force to improve health. This category includes techniques designed to manipulate, massage, or
stimulate the soft tissues of the body.9 “It usually involves lateral
stretching, linear stretching, deep pressure, traction and/or separation”39 of connective tissue. They may be applied to either articular or nonarticular soft tissues.
Although joint movement may be produced or improved as
a result of the application of soft tissue manipulative procedures,
the induction of joint movement is not a necessary or common
Chapter 4â•… Principles of Adjustive Technique |
Box 4-3
Soft Tissue Manipulative Procedures
Massage: the systematic therapeutic application of friction,
stroking, percussion, or kneading to the body.
Effleurage (stroking)
Pétrissage (kneading)
Friction
Pumping
Tapotement (tapping)
Vibration
Roulemont (rolling)
Therapeutic muscle stretching: a manual therapy procedure
designed to stretch myofascial tissue, using the principles
of postisometric muscular relaxation and reciprocal
inhibition
Proprioceptive neuromuscular facilitation (PNF)
Active release (ART)
Postisometric relaxation (PIR)
Contract-relax-antagonist-contract (CRAC)
Proprioceptive rehabilitation
Point pressure techniques: application of sustained or
progressively stronger digital pressure; involves stationary
contacts or small vibratory or circulatory movements
Nimmo (receptor tonus technique)
Acupressure
Shiatsu
Reflexology
Body wall reflex techniques
Visceral manipulation: a manual method for restoring
mobility (movement of the viscera in response to
voluntary movement or to movement of the diaphragm
in respiration) or motility (inherent motion of the viscera
themselves) of an organ, using specific gentle forces.
Modified from Barral JP, Mercier P: Visceral manipulation, Seattle, 1988, Eastland Press.
component of soft tissue procedures. The justification for a separate classification is to draw attention to their principal application
in the treatment of soft tissue disorders that may be nonarticular.
Soft tissue manipulative procedures are used to alleviate pain; to
reduce inflammation, congestion, and muscle spasm; and to improve
circulation and soft tissue extensibility.31 In addition to their use as
primary therapies, they are frequently used as preparatory procedures
for chiropractic adjustments. Soft tissue manipulation tends to relax
hypertonic muscles so that when other forms of manual therapy are
applied, equal tensions are exerted across the joint.
There are numerous named soft tissue manipulative procedures;
Box 4-3 provides a list of some of the common methods that are used
in manual therapy. Chapter 7 provides detailed descriptions of nonthrust joint mobilization and soft tissue manipulative procedures.
INDICATIONS FOR ADJUSTIVE THERAPY
The assessment and determination of whether a given health care
disorder is suitable for a trial of adjustive therapy depends largely
on the doctor’s clinical examination skills and experience. To deter-
89
mine if a given health complaint is manageable with chiropractic
care and adjustive therapy, the doctor must first form a clinical
impression based on the patient’s presentation, physical examination, and any indicated laboratory tests. The ability to thoroughly
evaluate and triage disorders of the NMS system and distinguish
those conditions that are appropriate for chiropractic care is critical. Differentiating mechanical from nonmechanical conditions,
assessing the source of the presenting complaint, and understanding the potential pathomechanics and pathophysiology of the
disorders being considered for chiropractic care are crucial
elements for successful treatment.
Appropriate treatment decisions are founded on an understanding of the natural history of the disorder being considered for
treatment and an assessment of the risks versus the benefits of the
considered therapy. If it is determined that the patient is suffering
from a condition appropriately treated with chiropractic care and
other contraindications have been ruled out, the presence of such
conditions provides sufficient justification for a trial of adjustive
therapy. If care is initiated, monitoring procedures must be maintained to assess whether the patient’s condition is responding as
expected or is deteriorating. If treatment does not provide results
within the expected time, it should be terminated, and other
avenues of therapy should be investigated.
MECHANICAL SPINE PAIN
Conditions inducing pain and altered structure or function in
the somatic structures of the body are the disorders most frequently associated with the application of manual therapy. The
causes and pathophysiologic changes that induce these alterations are likely varied, but are commonly thought to result
from nonserious pathologic change commonly lumped under
the category of nonspecific spine pain. In the low back, 85% to
90% of complaints are estimated to fall within this category.43,44
Specific pathologic conditions, such as infection, inflammatory rheumatic disease, or cancer, are estimated to account for
approximately 1% of presenting low back pain (LBP) complaints.45 Nerve root (NR) pain caused by herniated disc or spinal stenosis is estimated to account for 5% to 7% and referred
LBP resulting from visceral pathologic conditions accounts for
approximately 2%.45
The differentiation of mechanical from nonmechanical spine
pain should begin with an evidence-based clinical examination.
A “diagnostic triage” process based on a thorough history and brief
clinical examination is recommended by numerous national and
international guidelines as an efficient first step.46-48 This process
is most commonly referenced relative to LBP, but is applicable to
any axial spine pain complaint. The triage process is structured
to identify any red flags, ensure the problem is of musculoskeletal origin, and classify suspected musculoskeletal problems into
three broad categories before beginning treatment. The three major
categories are back pain caused by a serious spinal pathologic condition, back pain caused by NR pain or spinal stenosis, or nonspecific (mechanical) LBP. If the history indicates the possibility
of a serious spinal pathologic condition or NR syndrome, further
physical examination and indicated testing should be conducted
before considering treatment.
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The chiropractic profession postulates that nonspecific back
pain is not homogeneous and a significant percentage of mechanical spine pain results from altered function of spinal motion segments. Recent efforts have been directed toward investigating
models of differentiating nonspecific spine pain patients into
specific subcategories.49,50 Evidence is emerging that categorization and “subgrouping” of nonspecific (mechanical) spine pain
patients can lead to improved patient outcomes.51,52 Although
models for subgrouping nonspecific spine pain patients have been
based on both diagnostic and treatment categories,50,53 both share
the premise that grouping patients by shared collections of signs
and symptoms will lead to category-specific treatment and more
effective outcomes.
Imbedded in the process of subgrouping spine pain patients is
the principle that joint adjustments (HVLA thrust-joint manipulation) are not necessarily the most effective treatment for all
mechanical spine pain patients. Patients identified with altered
spinal or extremity function are most suitable for manipulation.
Other diagnostic categories such as clinical spinal motion segment
instability or impaired motor control are examples of treatment
categories in which continued joint manipulation may not be
appropriate and a trial of rehabilitative or proprioceptive exercise
would be more suitable.
JOINT SUBLUXATION/DYSFUNCTION
SYNDROMES
The chiropractic profession commonly labels functional alterations of spinal motion segments as joint subluxation or joint dysfunction syndromes. Furthermore, conditions successfully treated
with adjustive therapy are often deemed to incorporate altered
joint function as a central, associated, or complicating feature.
This is not to imply that chiropractors treat just joint subluxations or dysfunction. Joint subluxation/dysfunction syndromes
are commonly associated with other disorders of the NMS system,
and it is crucial that chiropractors accurately identify the complex
nature of the conditions they are treating. To simplify and reduce
all chiropractic care to the detection and treatment of subluxation
syndromes misrepresents the broader range of disorders that are
effectively treated by chiropractors. Diagnostic oversimplification
runs the risk of boxing chiropractors into a limited role—a role in
which chiropractors are perceived as providing limited treatment
for a very limited number of NMS disorders.
Although the evaluation of joint function is a critical step in
the process of determining whether and how to apply adjustive
therapy, the identification of subluxation/dysfunction does not
conclude the doctor’s diagnostic responsibility. The doctor must
also determine if the dysfunction exists as an independent entity or
as a product of other somatic or visceral disease. Joint subluxation/
dysfunction may be the product of a given disorder rather than
the cause, or it may exist as an independent disorder worthy of
treatment and still not be directly related to the patient’s chief
complaint. Pain in the somatic tissues is a frequent presenting
symptom in acute conditions related to visceral dysfunction, and
musculoskeletal manifestations of visceral disease are considered
in many instances to be an integral part of the disease process,
rather than just physical signs and symptoms.54
Before adjustive therapy is applied, the doctor needs to eliminate
serious pathologic conditions (red flags), consider whether the identified joint subluxation/dysfunction is negatively affecting the patient’s
health, exclude contraindications, and determine if the benefits of
adjustive therapy outweigh the risks. If therapeutic procedures outside the doctor’s scope of practice are indicated, referral to another
chiropractor or other health care provider must be made.
Clinical Findings Supportive of Joint
Subluxation/Dysfunction Syndrome
Joint Assessment Procedures
The evaluation of primary joint subluxation/dysfunction is a
formidable task complicated by the limited understanding of
potential underlying pathomechanics and pathophysiologic conditions.55 In the early stages of primary joint subluxation/dysfunction, functional change or minor structural alteration may be the
only measurable event.56,57 Evident structural alteration is often
not present, or none is measurable with current technology, and
a singular gold standard for detecting primary joint subluxation/
dysfunction does not currently exist. Therefore, the diagnosis is
based primarily on the presenting symptoms and physical findings
without direct confirmation by laboratory procedures.55
The physical procedures and findings conventionally associated
with the detection of segmental joint subluxation/dysfunction
(see Chapter 3 and Box 4-4) include pain, postural alterations,
regional ROM alterations, intersegmental motion abnormalities,
segmental pain provocation, altered or painful segmental end-range
loading, segmental tissue texture changes, altered segmental muscle
tone, and hyperesthesia and hypesthesia. Although radiographic
evaluation is commonly applied in the evaluation for joint
subluxation, it must be incorporated with physical assessment
procedures to determine the clinical significance of suspected joint
subluxation/dysfunction.
At what point specific physical measures are considered abnormal or indicative of joint dysfunction is controversial and a matter of ongoing investigation.58 The profession has speculated about
the structural and functional characteristics of the optimal spine,
but the degree of, or combination of, abnormal findings that are
necessary to identify treatable joint dysfunction has not been confirmed.59-62 Professional consensus on the issue is further clouded
by debates on how rigid a standard should be applied in the assessment of somatic and joint dysfunction and whether the standard
should be set relative to optimal health or to the presence or absence
of symptoms and disease. Until a professional standard of care is
Box 4-4
1.
2.
3.
4.
4.
6.
7.
Clinical Features of Joint Dysfunction
Local pain: commonly changes with activity
Local tissue hypersensitivity
Decreased, increased, or aberrant joint movement
Altered or painful joint play
Altered and or painful end-feel resistance
Altered alignment
Local palpatory muscle hypertonicity/rigidity
Chapter 4â•… Principles of Adjustive Technique |
established, each practitioner must use reasonable and conservative clinical judgment in the management of subluxation/dysfunction. The decision to treat must be weighed against the presence
or absence of pain and the degree of noted structural or functional
deviation. Minor structural or functional alteration in the absence
of a painful presentation may not warrant adjustive therapy.
The evaluation for and detection of joint restriction should not
be the only means for determining the need for adjustive therapy.
Patients with acute spinal or extremity pain may be incapable of
withstanding the physical examination procedures necessary to
definitively establish the nature of the suspected dysfunction, yet
they may be suffering from a disorder that would benefit from
chiropractic care. A patient with an acute joint sprain or capsulitis (facet syndrome, acute joint dysfunction) may have just such a
condition, a disorder that limits the doctor’s ability to perform a
certain physical examination and joint assessment procedures, yet
is potentially responsive to adjustive treatment.63
The patient with an acute facet or dysfunction syndrome
typically has marked back pain and limited global movements.
Radiographic evaluation is negative for disease and may or may
not show segmental malalignment. The diagnostic impression
is based on location and quality of palpatory pain, the patient’s
guarded posture, global movement restrictions and preferences,
and elimination of other conditions that could account for a similar presentation.63 The physical findings that are often associated
with the presence of local joint dysfunction, painful and restricted
segmental motion palpation, and end feel are likely to be nonperformable because of pain and guarding.
The decision to implement treatment in such circumstances
must then be based on a determination of whether this is a condition that may respond to adjustive therapy. If this is the case, an
evaluation to ensure that manipulation can be delivered without
undue discomfort should be performed. This is accomplished by
placing the patient in the position of anticipated adjustment and
gently provoking the joint. If the patient is resistant or experiences
undue discomfort during joint testing, other forms of manual or
adjunctive care should be considered. Once the patient has progressed to a point at which full assessment is possible, a complete
examination to determine the nature and extent of the underlying
dysfunction must be performed.
OUTCOME MEASURES
Patient-oriented outcome measures (OMs) are procedures used
to measure a patient’s clinical status and response to treatment.
In the management of NMS conditions, this commonly incorporates measures that assess the patient’s pain symptoms, function
(impairment), disability (activity intolerance), and general health
status (Box 4-5).64,65
Box 4-5
Outcome Measures for Spine Pain
Regional mobility measures
Pain-reporting instruments
Physical capacity questionnaires
Physical performance measures
General health status
91
In the absence of definitive physical measures for the identification of manipulable spinal lesions, patient-oriented OMs provide a valid tool for measuring patient response to chiropractic
treatment. The NMS disorders commonly treated by chiropractors are symptomatic or have a significant effect on the patient’s
ability to function, establishing the patient as an excellent candidate for functional outcome assessment.55,64,66
Instead of relying solely on procedures traditionally used to
identify joint dysfunction/subluxation syndromes, practitioners
should also apply procedures that measure the effect their treatment is having on the patient’s symptoms and function. In this
context, the name and nature of the disorder become less of a
focus, and more attention is paid to how the patient is functioning
and responding to treatment. The critical issues are to establish
functional goals and monitor and document the patient’s progress
using reliable OMs.
OMs do not necessarily represent the pathophysiologic status of the condition being treated. Instead, they answer questions
about the quality or the perception of the patient’s life in comparison to the preillness state. OMs that evaluate functional status
typically allow the assessment of multiple dimensions of patient
functioning (e.g., physical and psychosocial). Many have welldemonstrated reliability and validity and stand as appropriate
measures for monitoring the patient’s response to treatment.64 As
such, they can be used to decide if a specific approach to dealing
with patient complaints is effective and efficient compared with
other approaches. It is the use of reliable and valid OMs in clinical studies and practices that will help quell the critical echoes of
unscientific claims.
OMs incorporate self-reporting instruments and physical assessment procedures. Self-reporting instruments generally take the
form of questionnaires that are used to quantify the degree of pain
or the severity of disability as a result of impairment. Examples of
tools that measure pain symptoms include the visual analog scale,
which measures and rates a patient’s pain intensity and response
to treatment; pain drawings, which identify the location and quality of pain; and the McGill pain questionnaire, which measures
sensory, cognitive, and motivational elements of pain. Pain intensity can also be evaluated through palpation or with algometry.
Palpatory assessment and location of pain have consistently demonstrated excellent reliability (see Chapter 3).
The patient’s perception of disability or activity intolerance is
commonly measured by any of a number of self-reporting instruments. The Oswestry Disability Questionnaire67 and the RolandMorris Questionnaire68 are common instruments applied in LBP
disorders. The Neck Disability Index69 has been developed and
applied for assessing disability associated with neck pain. Other
measures that may be incorporated include evaluation of general health and well-being (e.g., Sickness Impact Profile, SF 36,
EuroQol, and COOP Charts) and patient satisfaction surveys.65
The measurement of physical capacity for selected regional
muscles and joints can be evaluated by a variety of physical tasks
that measure ROM, muscle strength, and endurance. Normative
values have been established for such procedures and can be effectively and economically used to monitor treatment progress.70
Four low-tech tests have been studied and have shown good reliability and correlation with spinal pain and disability (Box 4-6).71
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Box 4-6
Spinal Physical Capacity Tests
Repetitive Squatting
Patient stands with feet about 15â•›cm apart, squats until the
thighs are horizontal, and then returns to the upright position.
Patient repeats every 2 to 3 seconds, to a maximum of 50.
Repetitive Sit-Ups
The patient lies supine with the knees flexed to 90 degrees
and ankles fixed. The patient then sits up, touching the thenar
aspect of the hand to the patella, and then curls back down to
the supine position. Patient repeats to a maximum of 50.
Repetitive Arch-Ups
The patient lies prone with the inguinal region at the end of
the table, arms at the sides, ankles fixed (by the examiner or
a strap), holding his or her trunk off the table at a 45-degree
flexion angle. The patient rises to a horizontal position and
lowers back down, with a maximum of 50 repetitions.
Static Back Endurance Tests
The patient lies prone on the table with the inguinal region at
the edge of the table, arms at the sides, ankles fixed (by the
examiner or a strap), holding his or her trunk off the table in a
horizontal position. The patient maintains the horizontal position for long as possible, for a maximum of 240 seconds.
Broader functional capacity or whole-body movement testing can
also be measured. Testing in this arena is more complicated and
time consuming. Functional capacity testing is often designed to
simulate specific workplace demands and includes such procedures as “lifting, carrying, and aerobic capacity, static positional
tolerance, balancing, and hand function.”64
CONTRAINDICATIONS TO AND
COMPLICATIONS OF ADJUSTIVE THERAPY
As mentioned previously, the clinical corroboration of subluxation/dysfunction syndromes is not, in and of itself, an indication for adjustive therapy. Dysfunction may be associated with, or
concomitant with, conditions that contraindicate various forms of
manual therapy. A complication is defined as a problem that occurs
after the application of a procedure. A contraindication is a problem identified before a procedure is applied that makes application of the treatment inadvisable because of its potential to cause
harm or delay appropriate treatment.
Manual therapy is contraindicated when the procedure may
produce an injury, worsen an associated disorder, or delay appropriate curative or life-saving treatment. Although certain conditions may contraindicate thrusting forms of manual therapy, they
may not prohibit other forms of manual therapy or adjustments
to other areas.72,73
When manual therapy is not the sole method of care, it may
still be appropriate and valuable in the patient’s overall health
management and quality of life. For example, manual therapy, if
not contraindicated, may help a cancer patient gain some significant pain relief and an improved sense of well-being. “Such
palliative care should be rendered concomitantly and in consultation with the physician in charge of treating the malignancy.”72
All disorders listed as potential contraindications to adjustive
therapy are not necessarily absolute contraindications to thrust
manipulation. Certainly, some disorders contraindicate any form
of thrust manipulation, but many potentially risky conditions
depend on the stage of the disorder and its pathologic process.
Many of the disorders or defects identified as potential contraindications to manipulation are therefore relative contraindications.
A relative complication implies that caution should be used in applying
adjustive therapy and consideration given for possible modifications in the adjustive treatments provided. The decision to treat
depends on the individual circumstances of the presenting case.
For example, what is the patient’s age and state of health? What is
the nature of the potentially complicating pathologic condition?
Is the disorder in a state of remission or exacerbation, or is it in its
early or late stages of development?
Serious injuries resulting from adjustive therapy are very uncommon.74-86 Suitable adjustive therapy is less frequently associated with
iatrogenic complications than many other common health care procedures.83 The majority of spinal manipulation complications arise
from misdiagnosis or improper technique. In the majority of situations, it is likely that injury can be avoided by sound diagnostic
assessment and awareness of the complications and contraindications to manipulative therapy. Conditions that contraindicate or
require modification to spinal manipulation are listed in Table 4-1.
Although the incidence of injury from manipulation is extremely
low, mild associated transitory discomfort is not unusual. Adverse
reactions and reported complications to spinal thrust manipulation run the gamut from mild increased local discomfort to
very rare but serious permanent neurologic complications or
death.87,88 The best available evidence indicates that chiropractic care is an effective option for patients with mechanical spine
pain37 and is associated with a very low risk of associated serious
adverse events.89-91
Senstad, Leboueuf-Yde, and Borchgrevink,25 using a prospective clinic-based survey, studied the frequency and characteristics
of side effects to spinal manipulative therapy (SMT). Information
regarding any unpleasant reactions after SMT was collected on 580
patients and 4712 spinal manipulative treatments by Norwegian
chiropractors. The researchers report that at least one reaction
was reported by 55% of the patients some time during the course
of a maximum of six treatments. Treatments were not limited to
manipulation (36% of visits were soft tissue manipulation and
25% had both soft tissue and thrust manipulation). It is unknown
to what degree soft tissue manipulation may have affected the rate
of reported side effects. Therefore the findings of this study outline the rate of side effects for common chiropractic treatments,
but do not provide a precise rate for thrust manipulation alone.
The most common reactions were increased musculoskeletal
pain. Increased local discomfort accounted for 55%, headache
12%, tiredness 11%, or radiating discomfort 10%. The reactions
to treatment usually did not interfere with activities of daily living
and were rated as mild or moderate in 85% of the cases; 64% of
reactions appeared within 4 hours and 74% disappeared within
24 hours. A prospective multicenter cohort study (2007) evaluating
cervical manipulation and adverse events found very similar results.89
Table 4-1
Conditions That Contraindicate or Require Modification to High Velocity–Low Amplitude
Spinal Manipulative Therapy
Condition
Potential Complication
from Manipulation
Method of Detection
Management
Modifications
Atherosclerosis
of major blood
vessels
Blood vessel rupture
(hemorrhage)
Dislodged thrombi
Soft tissue and mobilizing
techniques with light or
distractive adjustments
Referral to vascular surgeon
Vertebrobasilar
insufficiency
Wallenberg syndrome
Brainstem stroke
Palpation
Auscultation
X-ray examination
Visualization
Doppler ultrasound
History
Doppler ultrasound
Angiography
MRA
Aneurysm
Rupture
Hemorrhage
Tumors
Metastasis to spine
Pathologic fracture
Disease progression
Fractures
Severe sprains
Increased instability
Delayed healing
Increased instability
Osteoarthritis (late
stage)
Neurologic compromise
Increased pain
Radiograph
Uncarthrosis
Vertebral artery
compromise or dissection
Radiograph
Clotting disorders
Spinal hematoma
Osteopenia
(osteoporosis)
Pathologic fracture
Space-occupying
lesions
Diabetes (neuropathy)
Permanent neurologic
deficits
Unresponsiveness to pain
History of anticoagulant therapy
Pulse
Bruises
History of long-standing steroid
therapy
Postmenopausal females
Malabsorption syndrome
Nutritional deficiencies
Anticonvulsive medication
X-ray examinations
MRI
CT (myelography)
Laboratory findings
Examination of lower extremities
Skin (trophic changes)
Pulse
Symptom amplification
Waddell scale
Libman test
Mental status evaluation
Malingering
Hysteria
Hypochondriasis
Alzheimer disease
Prolonged treatment
Treatment dependency
Inappropriate response or
unresponsiveness to pain
or treatment
Irregular pulse
Abdominal palpation
Auscultation
X-ray examination
Palpation
X-ray examination
Laboratory findings
MRI
CT
Radiograph
CT
Stress x-ray examination
Motion palpation
No cervical thrusting techniques
Referral to anticoagulant therapy
Referral to vascular surgeon
Referral*
Referral*
If severe, referral*
If not, manipulation of areas of
fixation
Mobilization
Gentle manipulation
Distractive adjustments
Gentle traction
Mobilizing and soft tissue
techniques
Forceful manipulation
contraindicated
Forceful manipulation
contraindicated
Mobilizing technique with
light€distractive adjustments
Referral*
Referral*
Referral* for psychologic
evaluation
Active care
Gentle manipulation
Mobilizing and soft tissue
techniques
MRA, Magnetic resonance angiography; MRI, magnetic resonance imaging; CT, computed tomography.
*Note: Although referral for medical treatment of the specific pathologic process is deemed appropriate and necessary, it does not preclude the patient from receiving manipulative therapy to
unaffected areas or, in some cases, to the areas of pathology for symptomatic relief or quality-of-life enhancement.
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The study involved 79 chiropractors and 529 subjects over 12
months. The most common adverse events were with a mild to
moderate transitory increase in musculoskeletal pain (70% to
75%). No serious adverse events were reported during the study
period.
The overwhelming majority of reported side effects fall within
the category of acceptable reactions. Their occurrence is likely a
normal product of manual therapy and the mobilization or stimulation of periarticular soft tissues. There were no reports of any
serious complication in this study, and 5% of patients or less
reported uncommon and transitory reactions of dizziness, nausea,
or hot skin.
Kleynhans77 has suggested labeling reactions as normal and
adverse to distinguish those postadjustive reactions that are
expected from those that are unwanted. Normal reactions reflect
the minor increased discomfort that is anticipated to occur in a
significant percentage of patients who have been successfully
treated. Adverse reactions reflect the more uncommon reactions
that lead to more significant discomfort and temporary or permanent impairment.
Dvorak and colleagues84 have proposed a more detailed division of postadjustment effects, including two major categories
(reactions and complications) and four subcategories (Box 4-7).
Box 4-7
Adjustive Side Effects
REACTIONS
Adequate Reaction
Onset 6 to 12 hours
Mild subjective symptoms
Local soreness
Tiredness
Headache
No decreased work capacity
Less than 2 days’ duration
Spontaneous remission
Exceeding Reaction
Onset 6 to 12 hours
Objective worsening of signs and symptoms
Interferes with work
More than 2 days in duration
Spontaneous remission
COMPLICATIONS
Reversible Complication
Onset within 2 days
Requires diagnostic or therapeutic interventions
Tissue damage
Patient can return to preoccurrence status
Irreversible Complication
Onset within 2 days
Requires diagnostic or therapeutic interventions
Permanent tissue damage and impairment result
Modified from Dvorak J et al. In Haldeman S, ed: Principles and practice of chiropractic,
Norwalk, Conn, 1992, Appleton & Lange.
Reactions are transient episodes of increased symptoms that
resolve spontaneously. They are not associated with any organic
worsening of the underlying condition or new iatrogenic injury.
Complications are associated with new tissue damage and require
a change in therapeutic approach.
Reactions are further subdivided into adequate (acceptable) and
exceeding. Adequate (acceptable) reactions are transient episodes
of increased discomfort or mild associated symptoms that resolve
spontaneously. Adequate (acceptable) reactions are subjective
complaints that do not last longer than 2 days and do not interfere with the patient’s work capacity. Exceeding reactions are associated with more pronounced discomfort, objective worsening of
the signs and symptoms, decreased work capacity, and a duration
longer than 2 days.
Complications are divided into reversible and irreversible categories. With reversible complications, the pathologic condition
associated with the incident is reversible, and the patient eventually returns to a preoccurrence state. Irreversible complications
result in some degree of permanent disability.
The low documented risk of serious injury resulting from spinal adjustive therapy does not release the doctor from the responsibility of informing the patient about the procedures to be
performed and of the potential for any significant associated negative consequences.91 The patient must understand the nature of
the procedure and give written, verbal, or implied consent before
therapy is applied. The patient’s consent to treatment must be
documented in his or her health record. Any unauthorized diagnostic evaluation or treatment is unacceptable and exposes the
doctor to the potential charge of malpractice as well as assault
and battery.
Patients have the right to know about significant risks and
treatment options before consenting to examination and care.82,91
Despite the concern that detailed discussion of rare complications would unduly alarm patients and lead many to reject beneficial treatment,92 patients should be informed in circumstances in
which “there is risk of significant harm.”93
What constitutes a material and significant risk is debatable
but typically interpreted widely by the courts. In a Canadian case
(Mason v. Forgie) involving cervical manipulation and subsequent
cerebrovascular accident (CVA), the rare but serious potential
complication was deemed material. In Canada, this has led to
professional guidelines requiring informed written consent before
applying a patient’s first cervical thrust manipulation.92
In the United States, guidelines and formal polices have not yet
been developed along the explicit lines that they have in Canada.
However, lack of documented informed consent is felt by the profession’s largest malpractice insurer, National Chiropractic Mutual
Insurance Company (NCMIC), to be a significant cause of action
for filing malpractice suits. This company recommends that all
practitioners contact an attorney in their area who specializes in
health care law for advice on the standards for obtaining informed
consent.
Cervical Spine
Critics of manipulative therapy in general, and chiropractic specifically, emphasize the possibility of serious injury from cervical
Chapter 4â•… Principles of Adjustive Technique |
manipulation while downplaying the benefits of cervical manipulative therapy.88 Although case reports of serious complications
associated with cervical manipulation are rare events,86,87,89 it has
required only the rare occurrence to “malign a therapeutic procedure that in experienced hands gives beneficial results with few
side effects.”93
Case reports of serious complications from cervical spine
manipulation include a range of neurovascular complications
including cerebrovascular strokes from injuries to the vertebral or
carotid arteries, cervical myelopathy or radiculopathy secondary
to meningeal hemorrhage or herniated discs, Horner syndrome,
and diaphragmatic paralysis.88,94 Other non-neurovascular injuries
such as pathologic fracture, dislocations of cervical vertebrae, disc
herniation, dislocations of atlas on axis as a result of agenesis of
the transverse ligament (found in Down syndrome), and rupture
of the transverse ligament (found in inflammatory arthropathies)
have also been reported.87,88 The case reports of postmanipulative
complications represent a very small percentage of patients receiving spinal manipulation. They inform us that rare postmanipulative complications may develop and continued clinical research
is indicated. However, they are primarily retrospective and cannot be used to establish a predicative cause-and-effect relationship
between any specific form of manual therapy and the development of serious complications.95
Cervical Artery Injury and Cerebrovascular Events
The proposed serious side effect of cervical manipulation that
receives the most attention is damage to the vertebral artery
and subsequent vertebrobasilar artery (VBA) stroke. Although
a biologically plausible mechanism has been proposed, a causal
relationship between cervical manipulative therapy and VBA
strokes has not been established.86,96-98 The initial injury is speculated to result from manipulation-induced disruption and
dissection of the vessel wall. Damage to the vessel wall is speculated to induce an occlusive vertebrobasilar infarct secondary to
thrombosis or embolism formation. The literature also contains
reports of postmanipulative internal carotid artery dissection
(ICAD) and neurovascular complications. However, a literature
review conducted in 2003 identified only 13 cases. The authors
concluded that the “medical literature does not support a clear
causal relationship between chiropractic cervical manipulation
and ICAD.”99
Vertebral Artery Anatomic Considerations. Any discussion
concerning the biologic plausibility and potential causal relationship between cervical manipulation and vertebral artery injury
should begin with a review of the relevant anatomic relationships. The vertebral artery, the first branch from the subclavian
trunk, becomes closely related to the spine by entering the transverse foramen at the sixth cervical vertebral level. It then passes
through the transverse foramen from C6 to C1, lying directly in
front of the cervical nerves and medial to the intertransverse muscles (Figure 4-3).
Accompanying the artery is the vertebral plexus of veins and
the vertebral nerve, composed of sympathetic fibers arising from
the inferior (stellate) ganglion. After leaving C2, they pass with the
artery through the transverse foramen of the atlas, necessitating
a sharp deflection outward, a tortuous course around the poste-
Basilar artery
95
PICA
Vertebral
artery
Figure 4-3â•… Relationship of the vertebral artery to the cervical spine.
PICA, posteroinferior cerebellar artery.
rolateral aspect of the superior articular process of the atlas. As
the artery heads posterior, it passes by the atlanto-occipital joint
capsule and through the arcuate foramen, which is formed by the
posterior atlanto-occipital membrane. As the artery travels over
the atlas, it lies in a groove in the posterior arch of the atlas, which
it shares with the first cervical nerve. This groove can range in
depth from a shallow indentation to a complete bony ring. It then
turns upward and runs through the foramen magnum into the
cranial cavity and passes to the lower border of the pons, where
it joins the opposite vertebral artery to become the basilar artery.
The basilar artery runs a relatively short course and then splits to
form the circle of Willis, which is joined anteriorly by the internal
carotid arteries.
At the foramen magnum, a branch comes off of each vertebral artery to unite with the anterior spinal artery that descends
on the anterior surface of the cord. These branches give off further branches, forming the posterior spinal arteries that supply
the cord down to the level of T4. Another branch of the vertebral artery, the posteroinferior cerebellar artery (PICA), leaves the
vertebral artery just before their conjunction. The PICAs are the
largest branches of the vertebral artery and run a tortuous course
along the lateral aspect of the medulla, to which they are the main
blood supply.100 The vertebrobasilar system also supplies the inner
ear, the cerebellum, most of the pons and brainstem, and the posterior portion of the cerebral hemispheres, especially the visual
cortex.
Branches from the vertebral artery also supply blood to the
facet joint structures, the NRs, and the dorsal root ganglia. These
branches then form free anastomoses with the anterior and posterior spinal arteries, both of which are derivatives of the vertebral
artery.101,102 Most vertebral arteries are markedly unequal in diameter. The diameter of one, usually the left, may be three times larger
than that of the right. One vessel may be congenitally absent.103
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| Chiropractic Technique
Axis (C2)
vertebra
Vertebral
artery
Atlas
vertebra
Vertebral
artery
Axis (C2)
vertebra
A C3 Vertebra
B
C3 Vertebra
Figure 4-4â•… Diagram illustrating the relationship of the vertebral
artery to the upper cervical spine. A, In the neutral position, the vertebral artery passes through the transverse foramen without any traction
or compression. B, During right rotation, the left vertebral artery is tractioned as the atlas rotates forward on the left.
Theoretic Mechanical Model of Vertebral Artery Injury. The
anatomy of the cervical spine and the relationship of the vertebral
arteries to neighboring structures make the arteries potentially
vulnerable to mechanical compression and trauma. Variation in
the diameter of the arteries is thought to contribute to obstruction
and thrombosis, and attention has been drawn to the potential
susceptibility of vertebral arteries at the atlantooccipital articulation.
Specific head and neck movements have been proposed as the
source of potential mechanical injury to the vertebral artery and
provide the potential link to cervical spine manipulative therapy.
End-range neck movements are speculated to affect vessel wall
integrity by inducing injurious compression or stretching of the
arterial wall.104 Rotation with extension has been proposed as
the most risky movement. The contralateral vertebral artery is
postulated as the vessel most at risk because of vessel stretching or
compression that occurs with rotation of the atlas (Figure 4-4).
The postulated sites and mechanisms for extraluminal vertebral artery obstruction associated with head movement include
the following:
1. Skeletal muscle and fascial bands at the junction of the first
and second vertebral segments
2. Adjacent osteophyte, particularly at C4–5 and C5–6
3. Between the C1–2 transverse processes, where the relatively
immobile vertebral arteries may be stretched or compressed
with rotary movements
4. By the C3 superior articular facet on the ipsilateral side of
head rotation
Traumatic compression or stretching of the artery wall may lead
to a subintimal hematoma or intimal tear (Figure 4-5). A subintimal hematoma may lead to partial or complete occlusion of the
lumen. Tearing of the intimal layer can lead to pooling of blood
that serves as a space-occupying lesion. Blood rushing past an intimal tear can also potentially dissect away the vessel wall, creating
a subintimal hemorrhage or dissecting aneurysm (see Figure 4-5).
A tearing of the intima results in exposure of the subendothelial
tissue and clot formation. With repair, no further problems may
be encountered, or a biochemical cascade and repair process may
be triggered, resulting in thrombus formation. The propagating
thrombus may impair blood flow, increase turbulence, and lead to
further clotting and thrombus growth (see Figure 4-5). Blood flow
may break off a portion of the thrombus, resulting in a floating
embolus and infarct where it lodges in a distal arterial branch. In
the case of the vertebral artery, this may result in occlusion of the
PICA. An infarct in the PICA results in a brainstem stroke referred
to as Wallenberg syndrome. It is characterized by clinical findings
associated with structures innervated by the cranial nerves. A less
common occurrence is occlusion of the basilar artery and more
serious neurologic complications (locked-in syndrome) with
conservation of only vertical ocular mobility and blinking.
Attempts to determine the relationship between neck movements and their effects on vertebral artery blood flow have led to a
number of Doppler ultrasound studies conducted on both cadaveric and human volunteers. Cadaveric studies have implicated
rotation as the single most likely movement to cause reduction in
blood flow. Lateral flexion and extension movements individually
were found to have little effect in altering blood flow. With pure
rotation, the contralateral artery was compromised more often.
Reduction in blood flow occurred toward the end of rotation but
still within the normal range of head motion. However, when
rotation was combined with extension, the ipsilateral artery was
involved as frequently as the contralateral artery.102,105,106
Studies conducted on healthy volunteers and subjects who
have a history of dizziness or positive positional tests have demonstrated mixed results. All studies conducted through 1996 have
used Doppler ultrasound evaluation of vertebral blood flow velocity. Results have ranged from complete reduction of blood flow to
no measurable change.107
Beginning in 1998, Licht and associates107 published the results
of a series of studies conducted with the aid of more advanced
digitized color-flow duplex Doppler ultrasound techniques. The
researchers found modest reductions in vertebral artery blood flow
in full contralateral rotation and a mild increase in vertebral artery
blood flow in ipsilateral rotation.107 Licht and associates108 believed
that many of the previous studies, which had demonstrated significant variations in the effects of neck positions on vertebral artery
blood flow, may have had less-than-accurate recordings as a result
of less sophisticated technology. Potential errors were speculated
to have resulted from inadvertently investigating the wrong vessel,
establishing an inappropriate angle of insonation, or missing the
vertebral artery as the patient’s head was rotated.
In 1999, Licht, Christensen, and Houlund-Carlsen109 expanded
the investigation and reported for the first time on the effects of
cervical rotation on blood volume flow through the vertebral
arteries. Measures of blood volume were more representative of
vertebral artery perfusion and clinically more relevant. In the
evaluations of the same 20 asymptomatic volunteers, no significant changes in vertebral artery blood volume was noted, despite
reductions in contralateral blood flow velocity. Blood flow volume was also unchanged 3 minutes after manipulation in subjects
deemed to have a cervical dysfunction.
In 1999, Yi-Kai and co-workers110 using transcranial Doppler,
found vertebral artery flow to be decreased with extension and
rotation in both cadaveric and human subjects. The most marked
reductions were noted when extension was coupled with �rotation.
Chapter 4â•… Principles of Adjustive Technique |
Subintimal hematoma
97
Intimal tear
Intima
Subintimal hematoma
Media
Adventitia
Thrombus
B
A
Direction
of flow
Direction
of flow
Subintimal hematoma
with dissecting aneurysm
Intimal tear
with embolic formation
Dissecting aneurysm
Thrombus
C
Embolus
D
Direction
of flow
Direction
of flow
Figure 4-5â•… Diagram illustrating vessel injury and the pathologic sequence of events that can lead to vessel occlusion. A, Subintimal hematoma. B,
Thrombus formation. C, Dissecting aneurysm. D, Embolus formation.
Extension coupled with rotation reduced blood flow in both vertebral arteries, but the reduction was most pronounced in the
contralateral vertebral artery. In 2002 Haynes conducted Doppler
velocimetric and magnetic resonance angiography (MRA) blood
flow assessments on eight healthy middle-aged adults.104 He concluded that end-range rotation did not demonstrate significant
stretching, narrowing, or major blood flow change in the contralateral vertebral artery. However, vessel stenosis and potential stress
from localized compression of the vertebral artery at the level of the
C2 transverse foramen was noted.
The cadaveric, human subject Doppler and MRA vertebral
artery studies do suggest a relationship between cervical movements and vertebral artery blood flow, but they do not answer the
question of whether cervical manipulative therapy has any negative effects. To investigate the potential for vessel injury, Symons
and colleagues applied manipulative-level forces to freshly dissected vertebral arteries.111 They dissected six vertebral arteries
from five fresh, unembalmed, postrigor cadavers and strained
the arteries on a materials testing machine. They concluded that
the strains associated with SMT “were almost an order of magnitude lower than the strains required to mechanically disrupt
the artery and were similar to or lower than the strains recorded
during range of motion testing.”111 They concluded that under
normal circumstances, a single thrust to the cervical spine would
be very unlikely to mechanically disrupt the vertebral artery.
Although this study does provide some biologic evidence that
healthy vertebral arteries are unlikely to be injured during cervical
manipulation, it cannot be generalized to clinical practice and
it does not address the issue of whether underlying arteriopathy
may make the vertebral arteries more susceptible to dissection.
Potential pathophysiologic models of vertebral artery dissection (VAD), not associated with major trauma, have been presented. They are based on the hypothesis that VAD is unlikely
to occur unless there is some environmental trigger or risk factor (e.g., infection, oral contraceptives, smoking, atherosclerosis,
trivial trauma associated with neck movements such as sporting
events or manipulative therapy) superimposed on an underlying
genetic predisposition (e.g., connective tissue disease, hyperhomocysteinemia, vessel abnormality).112 Further research is needed
to evaluate the validity of this hypothesis and determine whether
VAD risk factors can be identified.
Based on reviews of case reports, Terrett113 concluded that
94.5% of the reported cases of apparent post–manipulationinduced stroke involved neck rotation. Evaluation of the literature
also indicated that adjustments delivered to the upper cervical spine
as compared with the lower cervical spine were more frequently
associated with complications. Based on this analysis, Terrett114
and Terrett and Kleynhans115 reasoned that rate of injury could be
reduced by avoiding rotational tension or rotational manipulation
in the upper cervical spine. They subsequently recommended that
rotational manipulation of the upper cervical spine be abandoned
in favor of lateral flexion adjustments.
However, rotational-type adjustments are the most commonly
applied thrusting procedures to the neck, and the higher incidence
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| Chiropractic Technique
of injury may simply be a product of their common application.
A 1999 assessment97 of the literature supports this hypothesis.
Their literature review failed “to show a consistent position or
movement of the neck that could be considered particularly dangerous.”97 Almost all forms of manipulation have been implicated
and, if the relationship is temporal and not causal, or occurring in
patients with genetic predilections to trivial trauma, then almost
all potential minor activities of daily living could precede a VAD.
Adjustive procedures reported to minimize rotation and vertebral
artery injury, such as Gonstead and activator instrument adjustments, have also been associated with reported adverse reactions.
Moreover, primarily nonmanipulating practitioners (e.g., neurologists, vascular surgeons, and pathologists) have written the
reports of vascular accidents associated with manipulation. Their
interpretations of accounts, events, and procedures reported by
patients, relatives, or witnesses might be lacking in understanding and accuracy.113 A review of the English literature before 1996
revealed that 60.87% of the cases reported had no description of
the manipulation used, and only two of the reports had accurate
detailed information about the manipulative methods applied.97
This brings into question much of the data and conclusions that
have been drawn about who is delivering the manipulation and
the relationship between specific types of manipulation and vertebral artery injury.
If a practitioner wishes to minimize rotational tension during
the application of cervical adjustments, he or she need not abandon
rotational adjustive procedures. A more prudent approach would
be to apply only rotational manipulation when indicated and apply
it in a manner that minimizes full rotational tension with extension. It is important to distinguish between an adjustive procedure
that induces segmental rotation using maximal rotational prestress
from other adjustive procedures designed to minimize full rotational stress and tension on the vertebral artery. Inducing coupled
lateral flexion in the direction opposite the induced rotation
can prevent full rotational tension (Figure 4-6). Both influence
segmental rotation and mechanically may be similar. However,
the end-range procedure may place unnecessary stress on other
4-6 Figure 4-6â•… Right rotational adjustment in the
upper cervical spine with coupled left lateral flexion
and avoidance of coupled extension to minimize full rotational tension.
structures, including the vertebral arteries. It is recommended that
a “premanipulation” position be held for a short while and that
it be explained to the patient that this is the position that will be
used for treatment, thereby giving the patient an opportunity to
say whether the position causes any symptoms or discomfort.
Incidence of Manipulation-Associated Vertebral Artery Injury
and Stroke VAD and VBA strokes are exceedingly rare events. “It is
estimated that VBA dissections regardless of the etiology comprise
only 1.3 in 1000 cases of stroke per year. The dissection rate in
the general population is estimated to be 0.97 to 1.2 per 100,000
individuals,86,116 with major medical centers encountering only
0.5 to 3 cases of this disorder per year.”97 Because of the rarity of
this condition, estimates of the potential incidence of manipulation-linked VAD and stroke have relied on analysis of case reports,
series, surveys, and observational studies.80,81,83,88,113,117-124 Based
on a number of citations, the estimated incidence of VBA stroke
�following or occurring during cervical manipulation is reported to
range from less than 1 in 2 million to 1 in 3.8 to 5.8 million cervical manipulations.98,125
In 1983, Dvorak and Orelli121 conducted one of the first comprehensive surveys on incidence of complications after cervical
manipulation. They surveyed 203 practitioners of manual medicine in Switzerland and found a rate of one serious complication per 400,000 cervical manipulations, but reported no deaths
among an estimated 1.5 million cervical manipulations. In 1995,
Dabbs and Lauretti83 reported an estimated rate of less than one
stroke per 2 million cervical manipulations, based on a review of
the literature and CVA claims settled in a 3-year period by the
National Chiropractic Mutual Insurance Company. An extensive
survey conducted by Klougart, Leboueuf-Yde, and Rasmussen80
evaluated the records of all the Danish Chiropractors’ Association
members from 1978 to 1988 and found one case of VBA stroke
for every 1.3 million cervical manipulations. In the 10-year review
of Danish chiropractors’ records, they found only five cases,
with one case resulting in death. Another extensive literature
review, performed to formulate practice guidelines, concluded
that “the risk of serious neurological complications from cervical manipulation is extremely low, and is approximately 1 or 2
per million manipulations.”122 A comprehensive study published
by Haldeman, Kohlbeck, and McGregor97 in 1999 reviewed the
English literature for all reported cases of VBA dissection and
occlusion and documented 367 primary case reports. Of this pool,
160 (44%) were described as spontaneous and 115 as postmanipulation (31%), and 58 were associated with minor trauma and 37
with major trauma.97 Postmanipulation-linked cases represented a
smaller percentage of cases than spontaneous VAD.
Dobbs and Lauretti83 estimated that one VAD would occur per
100,000 chiropractic patients. This was based on the assumption
of one VBA-associated stroke per million manipulations, and 10 to
15 treatments per mechanical neck pain syndrome. Their estimates
approximate those of a recent best-evidence review by Miley and colleagues.118 They estimated that within 1 week of treatment, approximately 1.3 cases of VAD will occur for every 100,000 patients.
No relationship was noted in patients older than 45 years of age.
Of all CVAs, it is estimated that approximately one fourth will be
fatal126 and one third will resolve with mild or no residual effects.96
This results in an estimated death rate of 1 per 400,000 patients
Chapter 4â•… Principles of Adjustive Technique |
(0.0000025%) who seek chiropractic care.83 For comparison, a geriatric population of patients treated with nonsteroidal anti-inflammatory drugs (NSAIDs) for osteoarthritis had an estimated rate
of serious complication of 0.4% and an estimated death rate from
gastric hemorrhage of 0.04%. This rate of complication results in
an estimated annual mortality rate of 3200 deaths per year in the
United States from NSAID-induced ulcers among geriatric patients
treated for osteoarthritis.83 These rates of serious complication and
death are considered rare by medical standards and are many magnitudes the estimated incidence of reported serious complication
associated with cervical manipulation.83
Because the estimates of association between cervical
manipulation and VBA stroke have been predominantly based on
evaluation of case reports and surveys, some have suggested that the
risk of manipulation-linked VBA strokes may be understated.88 On
the other hand, there is also evidence to suggest that the incidence
of chiropractically attributed VBA strokes are overestimated.127,128
Terrett127 concluded that many of the reported cases were attributed
incorrectly to chiropractors. A significant number of the cases
reviewed implicated chiropractic manipulation when the therapist
performing the procedures was a medical doctor, physiotherapist,
or person without formal health care training. In addition, the
larger health care community, public press, and legal community
have become increasingly aware of a possible relationship between
manipulation and complications.129 In this environment, it seems
unlikely that serious complications of cervical manipulation would
be significantly under-reported.128
There have been three recent epidemiologic studies addressing the possible association of cervical SMT and VBA stroke. Two
case controls and one very large population-based case controlcase crossover study have been performed. The first by Rothwell,
Bondy, and Williams,130 published in 2001, compared 528 cases
of VBA stroke to 2328 matched controls. They identified a fivefold increased risk of VBA stroke in individuals younger than age
45 who had visited a chiropractor within the previous week. The
results were based on the identification of only six identifiable cases
and an estimated incidence rate of 1.3 per million cases. Smith
and co-workers,131 in 2003, compared 100 nondissection-related
stroke patients to 51 individuals diagnosed with cervical artery
dissection. No significant association between stroke or transient
ischemic attack (TIA) and neck SMT was identified. However, a
subgroup analysis did identify 25 cases of VAD in which a visit to
a chiropractor was six times more likely to have occurred within
the previous month than in the control group. The study was criticized for several methodologic shortcomings, including selection,
information, and recall bias.132
Although both studies identified a possible temporal relationship between SMT and VAD, it is not possible to attribute a definitive causal relationship between cervical manipulation and VAD
and VBA stroke by retrospective case control studies. It is possible
that all, or some percentage, of the postmanipulative-associated
VBA strokes are spontaneous and temporally not causally associated with cervical manipulation. VAD and VBA stroke may be
associated with chiropractic care because patients with VAD are
seeking treatment based on symptoms associated with a dissection
already in progress.133 Spontaneous VAD may initially present as
neck pain and headaches. Neck pain and headaches are a common
99
presentation for patients seeking chiropractic care. Furthermore,
in a number of the reported postmanipulation cases, symptoms
of vessel damage and stroke do not materialize until hours or days
after treatment. In such circumstances, it is possible that the treating doctor was administering manipulation to a patient with a
spontaneous artery dissection already in progress or to a patient
who developed a spontaneous dissection after treatment.
To further investigate the question of whether chiropractic
SMT is temporally or causally connected to VAD, Cassidy, Boyle,
and Cote86 compared the incidence of VBA stoke with chiropractic visits and primary care provider (PCP) visits. The hypothesis
was that if chiropractic care increases the risk of VBA stroke, then
the incidence of VBA stroke should be higher with chiropractic
visits than PCP visits. The study concluded that VBA stroke was
a very rare event in both patient populations, with no evidence
of an increased risk of occurrence with chiropractic care as compared with PCP care. The study population included all residents
older than 9 in Ontario, Canada. It evaluated all hospital-admitted
VBA strokes (818) between 1993 and 2002. In individuals
younger than 45 years, visits to chiropractors and PCP providers were associated with a threefold increased rate of VBA stroke.
There was no increased associated between chiropractic visits and
VBA stroke in individuals older than age 45.
Because it is unlikely that PCP care is associated with any
management procedures that are likely to cause stroke, the
results of this study support the authors’ conclusions that the
increased association between chiropractic visits and PCP visits
is likely the product of patients seeking care for symptoms associated with a VBA dissection before a stroke has occurred (VBA
prodrome).86
Screening and Prevention of Vertebral Artery Dissection.
Chiropractors have the potential to affect the development or
outcome of a VAD by either identifying patients with signs of
a dissection in progress or by avoiding diagnostic or therapeutic
procedures that could induce a VAD. Recent evidence indicates
that chiropractic cervical SMT is most likely temporally and not
causally associated with VAD and VBA stroke in that patients
seek care for symptoms associated with an undiagnosed VAD in
progress.86 In this situation, clinicians need to be trained to identify and immediately refer any patient with signs of an evolving
VAD.133
Other theoretic models have been presented suggesting that
VAD may also be associated with patients who may have a pre existing genetic predisposition to arteriopathy. This model suggests that
cervical artery dissection “is a product of an underlying predisposition triggered specifically by risk factors associated with environmental exposure, with or without trivial trauma.”112 In this situation
the identification of potential risk factors is paramount. Genetic risk
factors capable of compromising vessel wall integrity have been proposed and include connective tissue disease (e.g., Ehlers-Danlos
syndrome, Marfan syndrome), hyperhomocysteinemia, migraine,
and vessel abnormalities. Potential triggers include “(1) environmental exposure (e.g., infection, oral contraceptives), (2) trivial
trauma (common neck movements, sporting activities, manipulative
therapy), and (3) atherosclerotic-related disease (e.g., hypertension,
diabetes mellitus, smoking).”112 Although numerous risk factors
have been postulated for VAD, none have been clearly established.
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At this time no clinical diagnostic tests have been developed to identify patients at risk for a VAD. However, it is essential that chiropractors stay abreast of the evolving literature and, when possible,
develop the ability to identify potential risk factors for VAD.
The common risk factors associated with atherosclerosis
(hypertension, diabetes, smoking, oral contraceptive use, and
high cholesterol levels) are less likely to be associated with VAD
than non-VAD ischemic strokes.134 With the exception of cigarette smoking, the other typical vascular risk factors demonstrated a negative association with VAD. This correlates with the
findings that most patients who have developed postmanipulative VBA strokes are young to middle-aged individuals who are
apparently healthy; suffer from musculoskeletal complaints such
as head, neck, or shoulder pain; and have no significant history
of hypertension or hypotension. The most common age range for
VBA stroke is younger than 45, contradicting the impression that
this is a problem in the older adult population.113 Furthermore, a
history of successful cervical manipulation without complications
does not appear to reduce the risk of future complications with
manipulation.93,96,113,135
A 2005 systematic review of risk factors associated with
cervical artery disease (CAD) identified associations between
aortic diameter, diameter change of the carotid artery during
the cardiac cycle, alpha-1 antitrypsin genetic protease inhibitor
deficiency, migraine, trivial trauma, and age younger than 45.134
A weak association was found with high levels of homocysteine
and recent infection. Most of the reviewed studies had several
sources of potential bias or inadequate data analysis, leading the
authors to concluded that the relationship between arteriopathy
and CAD has been insufficiently studied.134
The potential for trivial trauma (including manipulationinduced trauma) to induce VAD has been widely discussed in the
health care literature and the popular media. A number of physical
activities and specific movements temporally associated with VAD
and VBA stroke has been reported. The majority of these activities are not associated with significant trauma and are likely the
result of a noncausal temporal relationship or the product of trivial trauma in a patient with pre existing arteriopathy (Box 4-8).136
A 2005 systematic review did not find any studies that suggested
“common neck movements pose an independent risk factor for
VAD.”134
Examination. Cervical manipulation should be preceded by an
appropriate problem-based history and physical examination. The
assessment should include a systems review and family health
history.98 Any identified cerebrovascular risk factors or concerns
should stimulate a “close observation of neurologic status.”98
Currently there is no established history or physical examination findings that predict whether a patient will develop a VAD.
However, there are clinical findings that appear to be more associated with the development of VAD. The identification of these
findings should raise the clinician’s index of suspicion and concern for the possibility of developing a VAD.98 The most extensive
monograph covering cervical spinal manipulation and cervical
artery incidents recommends the factors listed in Box 4-9 as the
most important elements to consider in the clinical assessment of
a patient being considered for neck manipulation.98 Those listed
in Box 4-10 are important features warning of possible CAD.
Box 4-8
Activities Associated with
Vertebrobasilar Artery Stroke
Childbirth
Head movements by surgeon or anesthetist during surgery
Calisthenics
Yoga
Overhead work
Neck extension during radiography
Neck extension for a bleeding nose
Turning the head while driving a vehicle
Archery
Wrestling
Emergency resuscitation
Stargazing
Sleeping position
Swimming
Dancing
Fitness exercise
Beauty salon activity
Tai Chi
From Terrett AGJ: Vertebrobasilar stroke following manipulation, West Des Moines, Iowa,
1996, National Chiropractic Mutual Insurance Company.
Box 4-9
Potential Warning Signs or Risk Factors
for Cervical Artery Dissection
1. Sudden severe pain in the side of the head or neck,
which is different from any pain the patient has had
before
2. Dizziness, unsteadiness, giddiness, and vertigo
3. Age <45
4. Migraine
5. Connective tissue disease
• Autosomal dominate polycystic kidney disease
• Ehlers-Danlos type IV
• Marfan syndrome
• Fibromuscular dystrophy
6. Recent infection, particularly upper respiratory
From Triano J, Kawchuk G: Current concepts in spinal manipulation and cervical arterial
incidents, Clive, Iowa, 2006, NCMIC Chiropractic Solutions.
Signs and symptoms indicative of vertebral artery insufficiency
(the five “Ds” and three “Ns”) and carotid artery insufficiency are
listed in Box 4-10.
The most important risk factors for developing a CVA appear
to be signs of vertebrobasilar ischemia (VBI) (e.g., dizziness, drop
attacks, dysarthria, and nystagmus) and a sudden onset of severe
pain in the side of the head or neck, which is different from any
pain the patient has had before.98 These may be signs of a VAD
in process and warrant further evaluation and possible need for
immediate referral.
Unfortunately, dizziness, vertigo, and disequilibrium are
symptoms that are not unique to patients suffering from VBI.
Chapter 4â•… Principles of Adjustive Technique |
Box 4-10
Signs and Symptoms of Vertebrobasilar
Ischemia
New and sudden onset of head, neck, or face pain
unfamiliar to the patient from prior experience
Five “Ds” and three “Ns”:
• Dizziness, vertigo, giddiness, light-headedness
• Drop attacks, loss of consciousness
• Diplopia, other visual disturbances
• Dysarthria
• Dysphagia
• Ataxia of gait, walking difficulties, incoordination of
extremities
• Nausea, vomiting
• Numbness on one side of the face or body
• Nystagmus
Signs and symptoms of carotid artery ischemia:
• Confusion
• Dysphasia
• Headache, anterior neck or fascial pain
• Hemianesthesia
• Hemiparesis or Monoparesis
• Visual field disturbances
From Triano J, Kawchuk G: Current concepts in spinal manipulation and cervical arterial
incidents, Clive, Iowa, 2006, NCMIC Chiropractic Solutions.
Disequilibrium secondary to cervical dysfunction is a common presentation, especially in patients who have had cervical
trauma.137,138 The dilemma faced by the doctor is how to differentiate vascular from nonvascular disequilibrium. A patient who
presents with VBI-like symptoms or has these symptoms triggered with positional testing may be suffering from cervical dysfunction, which could respond positively to manual therapy.139
Unfortunately, reliable clinical tools are not presently available to
differentiate vascular from nonvascular disequilibrium. Therefore
if the clinician has serious suspicion of VBI, he or she should refer
the patient for a cerebrovascular evaluation before administering
manual therapy. In the majority of cases in which cervical dysfunction and disequilibrium are suspected, the doctor can proceed
with a cautious trial of therapy. Indicated manual therapy includes
soft tissue manipulation, mobilization, and gentle adjustments.
Any gently preformed adjustments should not be applied in any
prethrust positions that aggravate the patient’s symptoms. If one
or two treatments of initial therapeutic trial substantially decrease
the patient’s pain, it is safe to assume that the pain is of musculoskeletal origin and proceed with additional procedures.98
If a patient develops any postmanipulation symptoms that
could indicate VBI, it is prudent to assume a vascular causal
condition. Although VBI is an unlikely cause of the symptoms,
therapy should be changed accordingly because of the disastrous
consequences that could develop if manipulative treatment is continued and appropriate referral not made.115 If mild postmanipulation symptoms (e.g., dizziness and disequilibrium) dissipate, it
is possible that the symptoms are cervicogenic in nature. At subsequent visits, it may be suitable to proceed with the manual therapies outlined previously.
101
Evaluation procedures intended to identify patients at risk
of manipulation-associated vascular compromise have been proposed. Specific “functional” procedures have also been advocated
and applied in clinical practice.136,140-143 There are a number of different procedures designed to functionally test the vertebral arteries (de Kleyn, George, Hautant, Houles, Wallenberg tests, etc.),
but they all attempt to provoke signs of VBI by inducing extension and extreme rotation of the neck. Unfortunately, all of the
applied functional testing procedures alone or in combination do
not increase the chance of identifying the patient at risk of having a manipulation-linked VBA stroke. The applications of functional vascular tests do not have any diagnostic value and are no
longer considered to be standard of care screening diagnostic procedures.98 Terrett113 made the following concluding remarks concerning functional vertebral artery vascular tests: “It makes no
sense to subject the patient to a screening procedure that is invalid
and only gives the practitioner a false sense of security regarding
the degree of risk for SMT.” This can only lead to the conclusion
that the tests should be abandoned for clinical and medicolegal
purposes, and should not be used for nonclinical risk management reasons.
Bruits and carotid arterial bruits specifically have been proposed as contraindications and are possible indications of vascular
pathologic conditions, but are not by themselves contraindications
to SMT.113 Furthermore, the reliability of auscultation has been
questioned. Ziegler and colleagues144 concluded that the presence
of bruits over the carotid artery is a very unreliable indicator of
CAD. CAD is even less frequently affiliated with SMT99 than
VAD, and the vertebral artery cannot be auscultated. If a bruit is
heard and is associated with other symptoms (such as headache,
neck pain, or whooshing sounds) or other pathologic conditions
(such as hypertension), further evaluation and referral are indicated before applying cervical manipulation.
Conclusions. Postmanipulation VAD and VBI are extremely
rare events. The majority of chiropractors go through their entire
careers without ever encountering this event.
An association between VAD dissection and chiropractic cervical manipulation has not been established and the relationship
may be temporal and not causal.86 Definitive risk factors for developing a VAD have not been established112 and there are no clearly
identified neck positions or manipulative procedures associated
with an increased risk of inducing this injury.97
At the present time (2010), no specific adjustment can definitively be said to have more risk than another. The current limited understanding of the mechanism VAD and its relationship
to rotational manipulation does not support recommendations to
avoid all rotational manipulation of the upper cervical spine. This
position is not supported by the clinical literature97 and is an
over-reaction to a procedure that when performed by a skilled
practitioner, is quite safe and therapeutically beneficial37,38,145-156
Despite the adherence to sound practice standards, the rare
postmanipulation ischemic stroke will likely continue to occur
because of our inability to identify those patients at risk of developing a spontaneous or postmanipulative-associated VBA stroke.
It is therefore absolutely imperative that the clinician be able to
recognize the signs of a VBI and take the appropriate steps to
minimize the pathologic effects.
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Although it is uncommon to experience VBI-like symptoms
after manipulation,24 if they do occur, specific steps must be followed. The most important first step is to not administer another
cervical adjustment.157 If the patient is experiencing a VBA stroke,
further manipulation will only delay appropriate referral and
management.
Symptoms indicative of a TIA or stroke represent a potential
medical emergency. Health care practitioners are responsible for
recognizing the symptoms of these events and taking appropriate
action. If a patient demonstrates or develops any pre- or postmanipulative symptoms indicative of VBI, it is prudent to assume a
potential vascular cause. Even if symptoms abate, there is a set of
signs or symptoms that should trigger consideration for an immediate referral. Every clinical situation is potentially different, but
the treating clinician must have good clinical justification to not
refer a patient for evaluation if any of the symptoms or findings
outlined in Box 4-11 are encountered. If an immediate referral is
indicated, the practitioner should call 911 and have the patient
transported to the nearest emergency room. It is important to
communicate the patient’s status, and the practitioner’s concern
that the patient may be suffering from a stroke. It is important
to communicate any precipitating events, including whether the
symptoms developed after the delivery of cervical manual therapy.
If indicated, advanced imaging can confirm the presence of an
ischemic stroke, and immediate administration of anticoagulant
therapy is in order. This therapy must be delivered within 3 hours
to effectively dissolve an offending clot. A quick referral and effective communication will expedite necessary care and have dramatic effects on decreasing morbidly and improving outcomes.
If more moderate, nonurgent but suspicious (e.g., dizziness,
disequilibrium) postmanipulative symptoms develop, the patient
should be closely monitored. Allow the patient to rest quietly and
if the condition does not improve within a reasonable time, the
patient should be transported to the nearest emergency room for
evaluation. Appropriate evaluative and procedural steps are outlined in Box 4-12.
Postmanipulation VBI-like symptoms are not necessarily indicative of vertebral artery injury or a developing VAD. Maigne10
postulated that VBI-like symptoms can be the product of stimulation of the vertebral nerve and the accompanying sympathetic
plexus. This stimulation in turn is hypothesized to induce spasm
of the vertebrobasilar arteries and a transient cascade of symptoms,
including vertigo, temporary loss of balance, nausea, and head-
Box 4-11
Postmanipulation Symptoms
Indicating Need for Immediate Referral
Impaired or loss of consciousness
Slurred speech
Drop attacks (sudden loss of strength in lower extremities)
Visual field disturbances
Difficulties with speech or swallowing
Paresis or paralysis of any limb
Paresthesia in one or both sides of the face
Ataxia or clumsiness of upper or lower extremities
Box 4-12
Steps to Follow with Possible
Postmanipulative Stroke Patient
1. Do not administer another cervical adjustment.
2. Do not allow patients to ambulate; keep them
comfortable.
3. Note all physical and vital signs (pallor, sweating,
vomiting, heart and respiratory rate, blood pressure,
and body temperature).
4. Check the pupils for size, shape, and equality.
5. Check the eyes for light and accommodation reflexes.
6. Test the lower cranial nerves (facial numbness or
paresis, swallowing, gag reflex, slurred speech, and
palatal elevation).
7. Test cerebellar function (dysmetria of extremities,
nystagmus, and tremor).
8. Test the strength and tone of the somatic musculature.
9. Test for somatic sensation to pinprick.
10. Test for muscle stretch and pathologic reflexes.
11. If condition does not abate and referral is deemed
necessary, communicate with the provider as to
findings, probable diagnosis, recommendation for an
MRA, and consideration of anticoagulant therapy.
From Ferezy JS: Neural ischemia and cervical spinal manipulation: The chiropractic neurological
examination, Rockville, Md, 1992, Aspen.
MRA, Magnetic resonance angiography.
aches. Terrett and Kleynhans cite Maigne, who has labeled this
pattern of postmanipulation symptoms as sympathetic storms.115
Although this is an engaging hypothesis, further investigation has
demonstrated limited neural control of vertebral blood flow,158
casting doubt on this theory. Another more plausible postulated
mechanism for postmanipulation, nonvascular VBI-like symptoms is manipulation-induced transient altered sensory and proprioceptive input from cervical joints.114
Thoracic Spine
Adjustive complications in the thoracic spine are rare. Reviews of
the literature reveal very limited information on types and rates of
postmanipulation injuries in the thoracic spine. Studies designed
to measure the incidence of adverse reactions typically do not
report incidence rates by spinal region.
The apparent low rate of serious injury in the thoracic spine
is probably a consequence of the region’s comparative stability
and the limited potential of manipulative treatments to damage associated neurologic or vascular structures. Although the
rate of serious injury is lower, it appears that the rate of mild
(acceptable) reactions to manipulation is similar or higher than
other regions of the spine. The only study to report comparative
rates of adverse reactions found the largest number of reported
mild (acceptable) reactions to manipulation to be in the thoracic
spine.159
As mentioned earlier, adverse reactions that exceed a mild to
moderate increase in discomfort are rare. They include sprains to
the costovertebral and costotransverse articulations, strains of the
Chapter 4â•… Principles of Adjustive Technique |
intercostal muscles, rib fractures, and rare reports of transverse
process fracture and hematomyelia.77,160
Excessive thoracolumbar torque in the side-posture position,
as well as inappropriately applied posterior-to-anterior (P-A) techniques, may cause thoracic cage injuries, particularly in older
adults. These problems are usually a result of excessive force in
relation to the patient’s size and physical condition. They can
be avoided by appropriate technique selection, application, and
evaluation.
Lumbar Spine
The incidence of serious complication from lumbar manipulation
is extremely low. A review of the “obtainable literature indicates
that, on average, less than one case occurs per year.”82 Reported
complications have been classified by Terrett and Kleynhans82 and
are listed in Box 4-13. Loads measured during the application of
lumbar and pelvic SP manipulation were comparable to those
encountered by airline baggage handlers and deemed to be below
an injury threshold.161
The most frequently described serious complications from
SMT in the lumbar spine is compression of the cauda equina by
a midline disc herniation at the level of the third, fourth, or fifth
intervertebral disc (IVD).77,85,162,163 The resultant cauda equina
syndrome (CES) is characterized by paralysis, weakness, pain,
reflex change, and bowel and bladder disturbances. Any patient
who has bilateral radiculopathies with distal paralysis of the lower
limbs, sensory loss in the sacral distribution, and sphincter paralysis may have CES and should be considered a nonmanipulable
case and a surgical emergency.162
Estimating the rate of serious lumbar manipulation complications is difficult because of the lack of prospective documentation
of complications and the uncertainty as to the number of manipulations delivered. In a review of 80 years of literature, Haldeman
and Rubinstein162 reported on 13 cases of CES that were apparently the result of manipulative therapy. Their literature review
identified 29 cases, but 16 of the cases were patients manipulated
under anesthesia. Manipulation under anesthesia is an uncommonly performed procedure, and including those cases does not
accurately reflect the risk of lumbar manipulation. In many of the
reported cases, both the chiropractic doctor and the emergency
room physician failed to comprehend the nature of the problem
and take appropriate action. This lack of prompt, appropriate
Box 4-13
Reported Complications of Lumbar
Manipulation
Disc-related complications
Diagnostic error
Vascular complications from thrombosis
Fracture in presence of osteoporosis
Manipulation in patient on anticoagulant therapy
Rib fracture
Inguinal and abdominal hernia
Unknown
103
treatment likely increased the incidence of serious complication
and residual impairment.
Shekelle and co-workers78 estimated the rate of post–lumbar
manipulation CES to be approximately 1 per 100 million manipulations. The rate was calculated by dividing the number of estimated lumbar manipulations delivered in the United States from
1967 to 1992 by the reported number (4) of postmanipulation
cases of CES in the United States. A 2004 review on the safety of
lumbar manipulation estimated that the risk of lumbar disc herniation (LDH) and CES at 1 event per 3.72 million manipulations.85
SIDE-POSTURE MANIPULATION AND
INTERVERTEBRAL DISC
Despite the extremely low rate of complication, controversy continues to surround the question as to whether SP rotary adjustments can injure the lumbar IVDs. The debate is primarily a
theoretic one, based on two opposing anatomic and biomechanical models. One position postulates that SP lumbar manipulation
produces a torsional shear force that is damaging to the discs. The
other postulates that the lumbar facets limit lumbar rotation and
protect the discs by preventing undue torsional stress. The following discussion looks at the underlying information central to positions presented by these opposing models.
Those advocating a position that lumbar SP rotary manipulation can potentially injure the disc often cite the biomechanical
work and theories of Farfan. Farfan and associates were the first
to advance the theory that repetitive rotational torsion and stress
could be damaging to the lumbar IVDs.164 He estimated that
approximately 90% of the torsional strength of a lumbar motion
segment is provided by the disc and facet joints, with the annulus providing the majority of the torsional resistance. His model
postulates that repetitive end-range torsional loading can lead to
tears in the annulus and disc degeneration. The injury process is
hypothesized to begin with circumferential separation of the outer
annular fibers, followed by the development of radial fissures,
internal disruption of the disc, and possible production of disc
protrusions and herniations.
A number of more recent studies bring into question the pure
rotational model of disc failure and its relationship to SP lumbar manipulation. These experiments support the position that
the posterior elements of the spine, including the facet joints and
ligaments, rather then the disc, are the key structures resisting torsion in the lumbar spine.165-167 The physiologic range of rotational
motion of the whole lumbar spine is approximately 10 to 15
degrees or approximately 2.5 degrees for each joint.139 The lumbar
joint space is small, and the articular cartilage must compress significantly (up to 60%) to allow up to 3 degrees of segmental movement. The primarily sagittally oriented lumbar facets provide an
interlocking mechanism that minimizes rotational mobility and
stress to the IVD. Movement must exceed 3 degrees of axial rotation (4% strain) before the annular fibers begin to demonstrate
microscopic failure. Full macroscopic failure does not occur until
12 degrees.168 Therefore, impaction of the zygapophyseal joints
provides protection for the IVD by limiting tension to the annulus
fibrosus to less than 4% strain.
Using a cadaveric model, Adams and Hutton165 demonstrated
that the torsion of the lumbar spine is resisted primarily by the
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facets and that the compressed facet is the first structure to yield
at the limit of torsion. Significant injury to the articular cartilage
and soft tissues was demonstrated before significant mechanical
stress was transferred to the IVD.165,169 The capsular ligaments of
the tension facet (facet being distracted during rotation) and the
supraspinous and intraspinous ligaments were found to be uninvolved or unimportant. This suggests that pure rotational damage
to the IVD could occur only after significant disruption of the
posterior joints. The same studies established that the disc was
more vulnerable to flexion injuries.170 Flexion is not inhibited by
the articular facets, and distortion and disruption of the posterior
annulus may occur with excessive flexion, especially when coupled
with positions of lateral bending, loading, and rotation.
Bogduk,168 aware of the protective effects of the posterior
joints, has postulated a biomechanical model of injury to the disc
that does not necessitate a preceding disruption of zygapophyseal
joints. His model incorporates excessive rotation coupled with
flexion. Flexion is presumed to tense the annular fibers, leaving
less available stretch before their rotational limits are exceeded.
Moreover, with the spine in a flexed position, the inferior and
superior articular processes are less engaged, allowing for more
segmental rotation. With excessive rotation, the normal axis of
rotation is envisioned to shift from its central location in the posterior one third of the disc to the impacted facet (compression
facet). The compression facet becomes the new axis of rotation,
allowing for excessive pivoting of the superior vertebra, resulting
in shear and torsion on contralateral facet and annular circumferential discal tears (Figure 4-7).
Axis
A
C
B
Fracture,
avulsion,
capsular tear
Fracture
D
Axis
Annular
tear
Figure 4-7â•… Forced rotation beyond the normal range may shift the
axis of rotation from its central location (A) to the impacted facet (B).
Continued rotation may lead to fractures of the impacted facets or capsular tears or avulsion fractures of the contralateral joint (C) and circumferential tears of the annular fibers (D).
Broberg171 studied the response to compression, shear, bending, and axial rotation of an IVD using a theoretic disc model.
He reported that the stiffness of the IVD increases considerably
with axial load. This finding implies that most experimental data
obtained at zero axial load may reflect poorly on real situations
involving weight bearing and axial loading. Within normal physiologic limits, bending, shear, or axial rotation does not seem to
constitute a risk of fiber rupture, except in combination with very
high axial loads. Moreover, with pure compression, the likelihood
of fiber rupture is not very great because end-plate failure occurs
earlier, before the rupture is manifest.172
It must be remembered that all of the previously described theories and speculations are based on studies conducted primarily
on cadavers. Most of the studies examining the effects of torsion
have been focused on the lumbar spine because of the high prevalence of LBP in society, and many of the studies were performed
on cadaver spine sections with the posterior elements removed.
The effects of torsional forces on the cervical and thoracic segments have not been adequately examined or studied. In the cervical region, the facets do not interlock as in the lumbar spine, and
greater axial rotation and torsion are available. The cervical spine
is the most mobile region of the spine, yet the incidence of disc
herniation here is much less frequently reported than in the lumbar spine. Conclusions reached with these studies, especially any
inference in their application to living human beings, must therefore be viewed with caution. The IVD may respond very differently to loads under normal physiologic loads or in circumstances
in which there is associated disc degeneration or motion segment
instability.
The clinical literature evaluating the potential risk of disc injury
from lumbar manipulation reveals a very low incidence of reported
manipulation-induced disc herniation. A review of the literature
through 1993 by Assendelft, Bouter, and Kripschild revealed only
56 case reports of lumbar manipulation complications attributed
to disc herniation.81 Nearly half (49%) of the cases occurred during manipulation under anesthesia, and the majority of the cases
(82%) progressed to CES. In addition, a number of the reported
cases cannot be clearly cited as evidence of manipulation-induced
disc herniation.163 In a number of the cases, the symptoms either
developed over time or at a point after treatment at which the
patient was involved in other activities that may have triggered a
worsening in his or her condition.162
Despite the very low level of documented postmanipulation
disc herniations in the literature, disc problems account for the
greatest percentage of malpractice claims filed against chiropractors. NCMIC insures the overwhelming majority of chiropractors, and the company paid claims on 1403 malpractice cases
from 1991 through 1995.173 This results in an annual average
of 280 paid claims per year for this company. During this time,
the percentage of filed claims for disc problems decreased slightly
from 29% in 1991 to 26.8% in 1995. In 1995, the incidence was
slightly higher in the lumbar spine (13.8%) than the cervical spine
(12.2%).174 If the percentage of disc complications for filed claims
and claims that were settled are the same, the number of claims
paid by NCMIC for disc-related problems in 1995 is approximately 75. Of this number, approximately 37 resulted from
lumbar manipulation.
Chapter 4â•… Principles of Adjustive Technique |
Although the total number of yearly claims paid for post–lumbar manipulation disc-related problems is a very low percentage
of patients receiving treatment, it is potentially an artificially elevated number. It is likely that the natural history of disc herniation
has led to a mistaken connection of causation between manipulation and disc herniation. Patients with disc herniation often present initially with back pain that over time may progress to include
leg pain. This often develops as associated NR inflammation and
compression persist. If the initial evaluation of a patient is equivocal and the patient is not informed that he or she may be suffering
from a disc herniation, subsequent progression of symptoms and
the subsequent diagnosis of a disc herniation may lead the patient
to erroneously assume that the manipulative treatment he or she
received caused the disc herniation.
Although the debate on the risk of disc injury with lumbar
manipulation has not been definitely resolved, the following tentative conclusions can be suggested:
1. The lumbar IVDs are protected from rotational stress and
injury by the lumbar posterior joints.
2. Marked force would have to be applied to injure the disc
with a rotational force.
3. Movement beyond normal range must be applied to injure
the disc and likely would occur only after significant injury
had been subjected to the posterior joints.
4. The disc is most vulnerable to flexion injuries. Loaded positions combining flexion and rotation are probably the most
risky.
5. The forces involved in skillfully delivered SP rotational
manipulation are not sufficient to injure a healthy disc.
6. In patients with disc herniation, manipulative positions that
incorporate excessive flexion and rotation should be avoided.
7. Before applying adjustments in patients with disc herniations,
an evaluation of lumbar movements should be conducted.
8. Adjustments should not be delivered in positions and directions that implicate increased NR compromise (i.e., directions that increase the intensity or distal distribution of the
patient’s leg pain).174,175
EFFECTS OF ADJUSTIVE THERAPY
Musculoskeletal
Treatment of NMS dysfunction and disease has historically been
the major reason for which chiropractors are consulted,3-8,176 and
NMS disorders are the conditions most commonly covered for chiropractic care by insurance companies and government health care
programs.3,8 Chiropractic patients have repeatedly expressed satisfaction with the quality and effectiveness of chiropractic care. In
comparative studies for the treatment of back pain, patients consistently rate chiropractic care as superior to medical care.177-186
Furthermore, authors who have reviewed the literature on spinal manipulation have concluded that sufficient evidence exists to
support the use of spinal manipulation in the treatment of a number of painful NMS conditions. This is most notable in the case of
mechanical back and neck pain and headache, in which a large body
of controlled clinical trials and systematic reviews has consistently
105
shown “spinal manipulation to be superior to sham/placebo or as
effective or more effective than an array of other comparison treatments.”37,38,74,180,187-198 There is presently more evidence supporting
manipulation as a therapy for LBP than for any other alternative.37
Guidelines on the management of LBP have also concluded that
SMT is a safe and appropriate treatment choice. The first major
U.S. government–directed guideline on the management of LBP
was published in 1994 by the Agency for Health Care Policy and
Research (now the Agency for Healthcare Research and Quality
AHRQ).192 This document represented a synthesis of the best evidence regarding the assessment and management of acute LBP in
the adult population of the United States. It consulted a panel of
experts drawn from the professions involved in treating LBP. There
were a number of principal conclusions. Most notably for the chiropractic profession were the recommendations that relief of discomfort can be accomplished most safely with nonprescription
medication or spinal manipulation. Bed rest in excess of 4 days was
deemed to be nonhelpful in most circumstances, and patients were
to be encouraged to stay active and return to work as soon as possible. Numerous subsequent professional, national, and international
guidelines on the treatment of LBP have reached similar conclusions.46,199-202 Most recent is the 2007 joint clinical practice guideline from the American College of Physicians and American Pain
Society, which recommends that “patients who do not improve with
self-care options consider the addition of nonpharmacologic therapy
with proven benefits.”46 This recommendation was made on moderate-level evidence and recommends the use of spinal manipulation for acute LBP and the following nonpharmacologic options for
chronic or subacute LBP: intensive interdisciplinary rehabilitation,
exercise therapy, acupuncture, massage therapy, spinal manipulation, yoga, cognitive-behavioral therapy, or progressive relaxation.46
The chiropractic profession has also consistently demonstrated
cost-effective treatment for back pain. Since 1980, the majority of
studies investigating the comparative cost-effectiveness of chiropractic
care have shown chiropractic treatment for LBP to be more cost-effective than medical care.180,184,188,191,203-207 An extensive review conducted
in 1993 for the provincial government of Ontario, Canada, concluded that chiropractic care was more cost-effective and would generate considerable cost savings if chiropractic services for treatment of
LBP were increased.180 Incorporation of chiropractic services within
a managed care organization decreased the use of radiographs, lowback surgery, hospitalizations, and average back pain episode costs.208
A large multicenter, community-based trial conducted in the United
Kingdom found that the addition of manipulation to “best [medical]
care” improved back function in both the short- and long-term. The
authors concluded that spinal manipulation is a cost-effective addition to “best care” for LBP in general practice.209,210
There are several exceptions in which the cost of chiropractic
care per episode of acute LBP was higher than care provided by
medical primary care providers.181,211 Chiropractic per-visit costs
were significantly lower, but total costs were higher because of
the higher number of visits per episode. The number of visits per
episode varied significantly among providers, indicating that total
costs were significantly elevated by a small percentage of providers
who delivered service well above the mean. Furthermore, medical
costs may have been artificially decreased in one study because of
the exclusion of associated hospital costs.
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Non-musculoskeletal
In addition to their successes treating musculoskeletal disorders
and dysfunction, most chiropractors have also noted positive
health effects from adjustive and manual therapy in areas outside
the musculoskeletal system. From the time of chiropractic’s origins, chiropractors have viewed their healing art as having wideranging health benefits.212 Philosophically, this is symbolized by
the chiropractic holistic health care viewpoint, which stresses the
important relationship between the structure and function of the
NMS system and its effects on homeostatic regulation and health
maintenance.213
Unfortunately, clinical research in the area of manual therapy
and somatovisceral disease is minimal. The functional visceral
conditions that may respond to chiropractic care, the circumstances under which they may respond, and the degree to which
they may respond have yet to be systematically studied and clearly
identified. It is still unknown and under debate if the removal of
mechanical malfunction of the spine may be helpful in treating
functional disorders. At present, there have been no appropriately
controlled studies that establish that spinal manipulation or any
other somatic therapy represents a valid curative strategy for the
treatment of any internal organ disease.214–235
Consequently, the profession should be cautious in implying or
guaranteeing a positive outcome for the manipulative treatment of
visceral disease. Further research involving large patient populations will be required before the somatovisceral effects of adjustive
therapy can be substantiated.236 At the same time, the profession
should not discount the potential positive health effects noted in
clinical practice. Patients without contraindications to manual
therapy who have a possible somatovisceral disorder should not
be refused treatment, but they should not be solicited with the
implied guarantee of a positive result.
Although the clinical effectiveness of chiropractic SMT for
mechanical spine pain has been demonstrated, very little is known
about how manipulation is producing a therapeutic effect. Several
hypotheses exist as to the mechanism by which chiropractic therapy affects the underlying NMS causes of joint dysfunction and
somatovisceral disorders. They include concepts that may be
broadly divided into mechanical and physiologic. The following
discussion touches on some of the proposed mechanisms, but is by
no means comprehensive.
Mechanical Hypotheses
In the mechanical arena, manual therapy is directed toward
reversing or mitigating the soft tissue pathologic condition and
mechanical dysfunction associated with disorders or injuries of
the NMS system. The soft tissue derangements responsible for
mechanical dysfunction may be initiated by trauma, repetitive
motion injuries, postural decompensation, developmental anomaly, immobilization, reflex changes, psychosocial factors, or aging
and degenerative disease. These injuries and disorders often result
in soft tissue fibrosis, adaptational shortening, loss of flexibility,
joint instability, and altered joint mechanics.30,237-241 The scope of
manual therapies available to treat mechanical joint dysfunction is
extensive. The selection and application of each should be based
on an understanding of the pathophysiology of the disorder being
treated and knowledge of the procedure’s potential therapeutic
effects and treatment outcomes. The major objective of adjustive
therapy is improved health and function through the alleviation of
musculoskeletal pain, and aberrant function.
In the early stages of soft tissue injury and repair, manual therapy
is directed toward decreasing pain and inflammation, preventing
further injury, and promoting flexible healing. Early appropriate
manual therapy and mobilization may minimize the formation of
extensive fibrosis and the resulting loss of extensibility.30,237,239-246
Excessive immobilization can retard and impair the healing process
and can promote further atrophy and degeneration in articular soft
tissue and cartilage.240-254 By promoting an early return to activity,
the detrimental effects of immobilization may be minimized. Early
activation promotes strong, flexible repair and remodeling and
breaks the pattern of deconditioning and illness behavior, which
can be detrimental to recovery.66,255,256 Gentle distractive adjustments, passive joint mobilization, friction massage, and effleurage
are commonly applied manual therapies in this stage.
If the initial injury to the connective tissue is minor, repair may
proceed quickly without significant structural change or resulting
impairment. If the tissue damage is marked, however, the ensuing
fibrous repair may result in “a scar, visible or hidden, which has
matured to fill the injured area, but lacks the resilience, strength,
and durability of the original tissue. Such an asymmetric scar, produced either by injury, degeneration, or surgical trauma, may produce disturbances of biomechanical performance.”255 Therefore,
when injury or degenerative disease results in contracture, stiffness, joint hypomobility, and chronic pain or impairment, manual therapies shift toward a more vigorous approach and are
directed toward the restoration of mobility and function. They
include adjustments, mobilization, therapeutic muscle stretching, connective tissue massage, trigger-point therapy, myofascial
release techniques, and the like.216 In this stage, manual therapies
are most effective when coupled with activities and exercises that
promote soft tissue remodeling and muscle strength. However,
applying spinal exercises without first incorporating an assessment
and treatment of joint dysfunction may be less effective. If joint
hypomobility persists, active exercise may stimulate movement at
the compensatory hypermobile joint instead of the hypomobile
joints. This may lead to the further breakdown and attenuation
of the joint stabilizing structures, which further complicate joint
stability.
Forces Generated During Adjustive Therapy
As mentioned previously, the clinical value of SMT for mechanical
spine pain has been demonstrated. However, the specific mechanism by which adjustments effect a reduction in symptoms has
not been determined.257 Adjustive therapy is assumed to have its
effect through the application of an external force. It is taken for
granted that this force will deform the spine, move its articulations, and stretch and stimulate associated soft tissues. The last
decade has seen significant evaluation and measurement of the
forces produced in the application of HVLA adjustments and
research is expanding on how those forces may be transferred to
the body. However, information regarding the effects of manipulative forces on biologic tissue is limited.161,257
Chapter 4â•… Principles of Adjustive Technique |
1000
900
Contact peak
807 N
800
Support
peak
761 N
Force (N)
700
600
500
400
300
200
157 N
123 N
100
Preload
0
250 200 150 100
50
0
50
100
Time (ms)
Figure 4-8â•… Comparison of force versus time for a typical adjustive thrust.
External forces associated with adjustments have been calculated by recording loads transmitted through flexible transducers
placed on the surface of patients, through the forces transmitted
to a load cell placed in the table below the patient258 or through
computer modeling.161 The typical manual HVLA adjustment is
characterized by a prethrust (preload) period and a thrust period.
The force magnitudes and durations of these periods have been
calculated and are illustrated in Figure 4-8.257,258
Herzog257 and Herzog, Kawchuk, and Conway259 measured
forces during the application of supine cervical, prone thoracic,
and side-lying sacroiliac adjustments. The peak thrust forces averaged 400â•›N for the thoracic spine and ranged between 220 and
550 â•›N of peak force during the application of sacroiliac adjustments. The peak forces, when converted from newtons to pounds,
range from 50 to 125â•›lbs of force. These forces corresponded to
approximately one third to two thirds of the treating doctor’s
body weight. Thrust duration times measured in the thoracic
spine ranged from 100 to 150â•›ms and never exceeded 200â•›ms.236
Force measurements in the cervical spine were markedly less than
other regions with preload and peak forces and averaged 100â•›N
of peak force. Thrust duration times were also significantly less
than in the thoracic and sacroiliac regions, ranging from 80 to
100â•›ms. Patient loads measured during the application of lumbar
and pelvic side posture manipulation were comparable to those
encountered by airline baggage handlers. The loads were deemed
to be below an injury threshold. The transmitted loads were
complex and varied based on patient position (PP) and method
selected.161
Kirstukas and Backman258 revisited the characteristics of prone
thoracic adjustments. They measured prone unilateral thrusts in
the thoracic spine using contact pressure measurements and table
force measuring equipment. Two separate chiropractors applied
six unilateral adjustive thrusts, divided equally over two sessions,
to the apex of the subjects’ thoracic spines. The results demonstrated significantly greater thrust forces than Herzog, Kawchuk,
and Conway,259 with one chiropractor averaging 630â•›N and the
other 960â•›N of peak thrust force. Thrust duration times averaged
96â•›ms and were consistent between doctors.
107
Kirstukas and Backman258 and Herzog, Kats, and Symons260
have reported on the distribution of thoracic prone manipulative
forces and the differences between applied forces, area of maximal contact pressure, and peak “effective” applied force. In the
thoracic spine Kirstukas and Backman estimated mean peak contact pressures at 680â•›kPa (100â•›psi) for one doctor and 1486â•›kPa
(215â•›psi) for the other.258 Peak contact pressure was focused under
the doctor’s proximal hypothenar to an area only a small fraction of the total area covered by the doctor’s contact hand. They
labeled this region the intense contact area and have defined it
as the area over which two thirds of peak contact pressure readings are recorded. Herzog, Kats, and Symons260 also determined
that prone thoracic adjustments had an “effective” peak force and
contact area that was much more focused than the full area of
anatomic contact. Based on these experiments, it appears that
short-lever, prone thoracic adjustments will have a significantly
more focused area of effective applied force than the overall
applied force.261
Although adjustive pretension and peak forces may vary between
doctors, certain consistent characteristics of HVLA adjustments
stand out. They all produce a high-velocity force with a consistent preload phase (preadjustive tension) and a rapid acceleration
phase. There is a consistent small drop in preload force before the
impulse is delivered.262 The adjustive thrust has a very short duration and short-lever adjustments have a focused area of contact
pressure and force. It also appears that trained chiropractors have
the ability to modify prethrust tension, peak velocity, and duration of adjustive thrust. These features are modified according to
the area that is being treated and the amount of prethrust tissue
resistance that is encountered.
Movements Generated During Adjustive Therapy
Our knowledge concerning the specific movements induced by
adjustive thrusts is limited but growing. The expanding body of
information on this topic does confirm that spinal movements are
produced with adjustive thrusts, but also indicates that the location and directions of movement may not fully match our clinical
assumptions.
The first significant study evaluating HVLA manual procedures
was limited to evaluating the movements generated by unilateral
P-A thrusts in the lower thoracic spine of fresh-frozen cadavers.263
Segmental translational and angular movements were measured.
The movements were recorded by using bone pins embedded in
the spinous process of three adjacent vertebra and high-speed cinematography. P-A and lateral translational movements averaged
0.5â•›mm and ranged up to 1â•›mm. Axial rotations averaged approximately 0.5 degree and were noted up to nearly 1 degree. Sagittal
rotations were greater, averaging approximately 1 degree, and were
recorded up to approximately 2 degrees.
Significant movement was localized to the contacted segment
and motion segments immediately inferior and superior to the
point of contact (Figure 4-9). None of the vertebral motion segments had pre existing fixations, and all had returned to their resting state within 10 minutes after the application of the adjustive
thrust.
Although this study cannot be generalized to living subjects,
it is the first study to demonstrate that high-velocity thrusts can
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| Chiropractic Technique
SMT
SMT
RTP
11
10
11
12
B
A Transverse plane
Sagittal plane
Figure 4-9â•… Diagram of the movements produced when a posterior-
to-anterior adjustment is applied to the right T11 transverse process
(RTP). A, Transverse view, demonstrates the transverse plane rotation that
is induced. B, Sagittal view, illustrates the anterior translation and sagittal
plane rotation (extension) that occurs at T10–11 and T11–12.
generate measurable spinal joint movement focused at the level of
adjustive contact and adjacent joints. This study also supports the
clinical assumption that unilateral prone thoracic P-A paraspinal
contacts are likely to generate forces that induce localized sectional
rotation and extension.
To evaluate lumbar manipulative movements, Ianuzzi and
Khalsa measured strains in the lumbar facet joint capsules of
cadaveric specimens during physiologic ROM movements and
simulated manipulation.264 They found that simulated manipulative forces induced movements primarily in the direction of
applied loads, were dispersed over fairly large areas, and induced
strains across facet joint capsules that were similar whether they
were delivered at the targeted joint or a nearby joint. They concluded that “despite the fact that vertebral rotations varied significantly in magnitude or direction with manipulation site, facet
joint capsule strain magnitudes were similar regardless of where
the manipulation was applied.”264 Although generalizability to
clinical practice and manual therapy is difficult because this study
was conducted on cadaveric specimens with manipulations simulated and produce by linear mechanical actuators, it does imply
“that segmental specificity may not be as important as previously
postulated in the efficacy of SM.”264
In two separate studies, Cramer and co-workers265,266 used MRI
to study the effect of side posture postioning and manipulation
on zygapophyseal (Z) joint movement and gapping in the lumbar spine. Both studies were conducted on healthy student volunteers (N 16, N 64) ages 22 through 30. Patients were scanned in
the supine neutral position, in left rotated side-lying posture with
left side up and then post–left rotation resisted mamillary push
adjustment (see Figure 5-230a). The positioning and adjustments
were applied to induce left lumbar rotation and gaping of the left
lumbar Z joint. Evidence of preadjustive positional gaping and
postadjustive gaping was evaluated by three radiologists. Lumbar
side posture spinal postioning demonstrated increased separation (gapping) of the Z joints over the neutral control position
(mean 1.18â•›mm). Lumbar adjustments induced mean separation
of 1.89â•›mm an increase of 0.71â•›mm over the nonadjusted side posture positioning controls. The increased postadjustive separation was
noted only in the group that was scanned in side posture position
versus the neutral position. It should be noted that the down-side
facet joints demonstrated an average −0.74â•›mm Â�compression Â�during
side posture postioning and −0.89 compression postadjustive
side posture position. The average �postadjustive side posture distractive gapping of the lumbar Z joints over the neutral control
was 2.24â•›mm—a significant amount of movement for a lumbar
Z joint. These studies establish that side posture lumbar-resisted
mamillary adjustments induce increased rotational distraction and
gapping in the up-side superior Z joints (side of adjustive contact)
during side posture-resisted mamillary adjustments.
A number of additional studies have been conducted to evaluate whether adjustments induce joint cavitation and whether the
cavitation can be localized to a targeted joint. These studies did
not attempt to measure the specific movements that might be associated with joint cavitation. The studies employed skin-mounted
microphones or accelerometers capable of detecting and localizing sound or vibrations associated with joint cavitation. The studies included assessment of supine cervical thumb pillar rotation
adjustment,267 side posture lumbar spinous pull, spinous push
and mammillary push adjustments,268,269 side posture lower sacroiliac SI push adjustments,268 and prone thoracic crossed bilateral
transverse and bilateral thenar transverse adjustments.269 Based on
the information provided by these studies, the following generalities can be noted for the specific adjustments performed and joint
cavitation:
1. Thrust adjustments commonly produce cavitations.
2. Single-level joint cavitation is uncommon in side posture
pelvic, lumbar, and supine cervical adjustments.
3. Supine cervical thumb pillar rotation adjustments overwhelmingly produce cavitation in the side opposite the
contact (94%).
4. Side posture pelvic adjustments commonly generate cavitation in the lumbosacral spine.
5. Prone thoracic adjustments and cavitation are more localized to
the level of contact than side posture and pelvic adjustments.
6. The targeted joint is more likely to cavitate when multiple
cavitations are produced.
7. Generalized cavitation accuracy is achievable with side
posture lumbar adjustments.
If level of cavitation is representative of level of focused adjustive force, it seems likely that adjustments are not as focused and
specific as clinically assumed. This raises the question of whether
adjustments need to be joint-specific to have maximal clinical
effect and the need to advance clinical research to address this
question. The majority of procedures evaluated to date have been
based on the premise that a precise level of spinal dysfunction
needs to be ascertained before effective treatment can be rendered.
Considerable effort is expended during the evaluation of patients to
ascertain whether a specific joint malposition or restriction exists.
Adjustments are then selected and applied with the presumption
that the correct method and vector must be selected to induce the
appropriate movement and therapeutic effect. However, if generalized adjustive clinical effects are equivalent to single-level clinical effects, then adjustive therapy decision-making might change
significantly.
Presently, many of the joint assessment tools, especially segmental motion palpation, have poor interexaminer reliability for
identification of a specific level of joint restriction. If identification of regional dysfunction were sufficient to establish effective
Chapter 4â•… Principles of Adjustive Technique |
bubble formation and collapse occur, and a cracking sound is
heard.274 The case for synovial joint cavitation and cracking is supported by experimental evidence conducted on metacarpophalangeal (MP) joints, the cervical spine, and the thoracic spine.23,275-282
Experiments conducted on MP joints indicate that there is a
linear relationship between an applied load and joint separation
up to the point of joint cavitation.276,278 At the point of joint cavitation, there is a sudden increase in joint separation without a
proportional increase in the applied load (Figure 4-10). When
the joint is reloaded after cavitation, there is no second cavitation,
and the joint separates to the same degree with a much more linear relationship between the applied load and the degree of joint
separation (Figure 4-11). The inability of the joint to undergo a
second cavitation persists for approximately 20 minutes, and has
been labeled the refractory period. The bubbles formed within the
MP joint cavitation consist of water vapor and blood gases and
have been measured at 80% carbon dioxide. The bubbles persist
for approximately 30 minutes before the gas is absorbed back into
solution.276-280
6
4
3
2
Rest
2
4
6
8
10
12
14
16
18
Tension in kg
Figure 4-10â•… Force displacement curve representing the effects of
joint separation and cavitation: As the joint tension increases with joint
surface separation, a quick and dramatic separation occurs, and a cracking noise is produced.
Cavitation
5
Separation in mm
As discussed earlier, adjustive thrusts are frequently associated with
a cracking sound. Typically, this occurs at the end range of passive
joint motion when a quick thrust overcomes the remaining joint
fluid tension. However, any procedure that produces joint separation has the potential to cause the cracking sound. The separation
of the joint is theorized to produce a cavity within the joint, the
induction of joint cavitation, and an associated cracking sound.
Cavitation is the “formation of vapor and gas bubbles within
fluid through the local reduction of pressure” and is a well-established
physical phenomenon. Evidence strongly suggests that it also
occurs during the application of spinal adjustive therapy, although
this premise has not been proven conclusively.23,272,273
It has long been known that a liquid confined in a container
with rigid walls can be stretched. If stretched sufficiently, cavitation
occurs. The pressure inside the liquid drops below the vapor pressure,
5
Crack
Separation in mm
treatment, then spinal joint motion palpation may have more clinical utility if applied within this context. This also has the potential to dramatically change the clinician’s perspective and alleviate
many of the clinical frustrations that occur when trying to establish a specific level of dysfunction.
Clinical research addressing the assumption that clinical outcome is better with specific identification of level of dysfunction
and application of specific adjustment is limited and addressed
by only one study at this point.270 The study evaluated patients
with neck pain who were randomized to receive cervical spine
manipulation at restricted levels identified by motion palpation
versus manipulation at levels randomly generated by a computer.
The results show that both groups had similar, and in some cases
dramatic, improvements in symptoms directly after receiving one
HVLA cervical adjustment. The results indicate that cervical endplay (EP) assessment–directed manipulation did not improve
same-day outcomes in pain or stiffness. The outcome lends support to the hypothesis that spinal manipulation may have a more
generalized, nonspecific mechanism of action in relieving symptoms. It implies that the mechanical effects associated with manipulation may lack spatial specificity and the adjustive vector may
not be as important as generally thought.
Although the evidence from this study indicates that using EP
to identify level of dysfunction does not improve the measured
outcome, it is still premature to abandon the specificity model.
It is the only study to clinically investigate this topic and it has a
number of limitations that significantly affect its clinical implications. Firstly, it measured the effects of only one adjustment on
immediate and same-day pain and stiffness reduction. It is likely
that manipulation has a dose-dependent therapeutic effect,271 and
this trial did not approximate the typical course of adjustive treatments. Adjustive treatments for a cervical mechanical pain syndrome average in the 6 to 12 range and occur over weeks. EP
assessment may also not be a valid indicator for same-day postmanipulative pain and yet valid in directing therapy that has an effect
on other clinical outcomes and pain and function over time. The
immediate pain and stiffness relief noted by both groups may also
be attributable to placebo or nonspecific effects associated with
assessment and treatment concealing differences between groups
that might develop over time.
109
4
3
2
1
Rest
2
4
6
8
10
12
14
16
18
Tension in kg
Figure 4-11â•… Force displacement curve illustrating that immediate
reloading of the joint after cavitation is not associated with a second cavitation, and the joint separates to the same degree with a much more linear
relationship between the applied load and the degree of joint separation.
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In manipulative experiments conducted on the thoracic spine,
joint cavitation typically occurred just before the peak adjustive
force. In a few cases, the cavitation occurred just after the delivery of the peak force.281 In the experiment conducted on the MP
joints, a small percentage of the manipulated joints did not produce an audible crack. It is postulated that the joint capsule in
these individuals was very tight, not allowing for sufficient joint
separation to produce cavitation22 (Figure 4-12). This observation
might offer an explanation for the clinical occurrence in which
some individuals need several adjustive treatments before joint
cavitation is produced. Over time, treatments might produce
enough flexibility in the joint capsule to permit joint cavitation.
Several mechanisms have been proposed for how joint cavitation produces the audible crack. Speculation centers on the
formation and collapse of gas bubbles or a rapid stretch of the
capsular ligament. Unsworth, Dowson, and Wright278 suggested
that cracking is not the result of bubble formation but the result
of the rapid collapse of bubbles caused by fluid flow. The crack is
viewed as a postcavitation phenomenon generated by the collapse
of bubbles as the newly formed bubbles rush from the higherpressure periphery to the relative low-pressure pocket generated
in the center of the distracted joint. Meal and Scott279 have more
recently shown that the crack produced in the MP joint and in
the cervical spine are actually double cracks separated by several
hundredths of a second. The significance of two separate recorded
cracks is a matter of speculation. The two sounds may be a direct
consequence of cavitation, the first crack being the product of gas
bubble formation and the second crack associated with the rapid
collapse of gas bubbles. Other possibilities include cavitation plus
soft tissue vibrations, stretching, or artifacts to account for the
second sound.
Brodeur272 has presented a slightly different model of joint cavitation and cracking based on a mechanism described by Chen and
Israelachvili.283 Within this model, the capsular ligament plays a
primary role in the production of joint cavitation and cracking.
During the first phase of joint manipulation, as the joint is being
loaded and the joint surfaces are being distracted, the joint and
the capsular ligament are seen as invaginating (drawing inward)
to maintain a constant fluid volume within the joint space. As
distractive pressure is increased, the capsular ligament reaches its
elastic limits and snaps away from the synovial fluid, producing
cavitation at the capsular-synovial interface. A rapid increase in
joint volume follows, and the gas bubbles formed at the periphery
rush to form a single coalesced bubble in the center of the joint
space (Figure 4-13). Brodeur272 speculates that the “snap-back”
of the capsular ligament is the event responsible for the audible
crack. He also proposes that this mechanism offers an explanation
for why some individuals with very tight or loose joint capsules do
not crack. “For loose joints, the volume of the articular capsule is
larger and traction of the joint does not cause a sufficient tension
across the ligament to initiate the snap-back of the joint capsule.
Similarly, an overly tight joint reaches the limits of its anatomic
integrity before the joint capsule can begin to invaginate.”272
Besides the cracking itself, cavitation is considered to be associated with several postadjustive phenomena: a transitory increase in
A
B
C
Separation in mm
3.0
2.5
2.0
D
E
F
Figure 4-13â•… Model of the changes in the periarticular structures dur-
1.5
Rest
2
4
6
8
10
12
14
16
Tension in kg
Figure 4-12â•… Force displacement curve in joints in which no audible
release could be generated. In these individuals, it is postulated that the
joint capsule is very tight, not allowing for sufficient joint separation to
produce cavitation.
ing a manipulation. A, The joint in its resting position. B, Long-axis distractive load applied to the joint. C, Once the tension exceeds a certain
threshold, the energy stored in the capsular ligament initiates an elastic recoil that causes the capsule to snap back from the synovial fluid.
Cavitation occurs at the capsular ligament–synovial fluid interface.
D, The sudden increase in joint volume temporarily decreases tension
on the capsular ligaments. E, The distractive forces continue to traction
the joint, stimulating high-threshold receptors. F, The joint volume is
increased, gases have coalesced into the central area, and the joint is significantly distracted relative to its resting position.
Chapter 4â•… Principles of Adjustive Technique |
passive ROM, a temporarily increased joint space, an approximate
20-minute refractory period during which no further joint cracking can be produced, and increased joint separation. Sandoz24 has
labeled the postadjustment increase in joint range of movement
paraphysiologic movement because it represents motion induced
only after cavitation (see Figure 3-23).
The postcavitation refractory period, discussed previously, and
associated phenomena may be explained by microscopic bubbles
of carbon dioxide remaining in solution for approximately 30 minutes.
During this period, the bubbles will expand with any subsequent
joint separation, maintaining the pressure within the joint. The
postcavitation expanded joint space appears as a radiolucency on
a radiograph of the distracted joint. The postcavitation increase in
joint space appears to be temporary and corresponds to the refractory period. Because the pressure within the joint cannot drop until
the gas bubbles are reabsorbed, no further cavitation can occur during this time.278 Furthermore, the force contributed by the stretching of fluid will be absent, causing a decrease in force holding the
joint surfaces together and thus resulting in the increased passive
ROM noted by Sandoz23,277 and Mireau and colleagues.284
As noted earlier, the crack associated with joint cavitation may
not be the product of the formation of gas bubbles, but rather a
rapid collapse of gas bubbles. In this model, the temporary increased
joint space cannot be explained by the persistence of gas bubbles.
An alternate explanation postulates that the increased joint space
persists from the excess synovial fluid that rushes to the decompressed center of the joint. The joint does not immediately return
to its precavitation resting space because synovial fluid is viscoelastic and slow-moving. The flow of excess synovial fluid between the
joint surfaces takes time to reestablish equilibrium and allow the
joint to return to its precavitation resting position.278
A study conducted by Mireau and colleagues284 brings into question whether the temporary increase in joint space after manipulation is a product of gas bubble formation. They compared the
resting joint spaces of subjects who did and did not have an audible crack with manipulation of the MP joints. Only 68% of the 62
subjects manipulated experienced an audible crack, yet the resting
joint space increased for both groups, with no statistical difference
noted between the groups. If the inaudible-crack group was able
to achieve a post-treatment increase in joint space, it suggests that
joint cavitation may have occurred, but without the intensity
necessary to record an audible release, or that some other unknown
phenomenon is at work for both groups.
Mireau and colleagues284 also studied the postmanipulation
joint mobility of the subjects who recorded an audible release and
those who did not. Both groups had 6â•›lbs of long-axis distraction
applied after treatment. In the audible-crack cohort, an increase in
joint space of 0.88â•›mm was noted, and an increase in joint space
of 0.45â•›mm was recorded for the group without an audible crack.
These findings suggest that there is some different physical effect
between those who experience an audible release and those who
do not. Perhaps a more profound separation of joint surfaces and
stretching of periarticular tissues is associated with joint cracking.
This supposition is further reinforced by the noted difference the
researchers reported between those individuals receiving a third
MP mobilization versus manipulation. The groups receiving joint
manipulation had a significantly larger post-treatment ROM.
111
Although articular cracking (cavitation) is commonly used by
chiropractors as evidence of a successfully delivered adjustment,272
the process of cavitation is not assumed to be therapeutic in and
of itself. Rather, it represents a physical event that signifies joint
separation, stretching of periarticular tissue, and stimulation of
joint mechanoreceptors and nociceptors. These events, in turn,
are theoretically responsible for alleviating or reducing pain, muscle spasm, joint hypomobility, and articular soft tissue inflexibility.236,272 Whether cavitation represents movement that is necessary
to produce a better outcome as compared with patients who do
not cavitate is largely unanswered. One study has compared the
outcome of patients who did and did not cavitate with manipulation. The population was a cohort of 71â•›LBP patients who received
a single sacroiliac manipulation. Subjects were reassessed 48 hours
after the manipulation for changes in ROM, numeric pain rating scale, and modified Oswestry Disability Questionnaire. Both
groups improved (21 noncavitators) and there were no clinically
significant differences between groups. This study was limited to
one area of the spine, evaluated only one adjustive method, and
the application of only one manipulation. These factors limit the
study’s generalizability and clinical implications.
The presence or absence of cavitation (an audible crack) is
also commonly presented as a means for distinguishing mobilization and thrust manipulation (adjustment).272 Manipulation
purportedly produces a cavitation, and mobilization does not.
Thrust manipulation is much more frequently associated with
joint cracking than mobilization. However, deep mobilization
may also be associated with cavitation. The original studies conducted on cavitation in the MP joints were the product of joint
mobilizations.276 If manipulation and mobilization were differentiated by the presence or absence of cavitation, a thrust manipulation, not associated with an audible release, would have to be
reclassified as a mobilization. Any therapy that induces enough
joint separation to overcome the fluid tension between synovial
joint surfaces can produce joint cavitation. Therefore, manipulation and mobilization should be distinguished by the velocity of
their application, not by the presence or absence of an associated
joint cavitation.
Whether repetitive joint cavitation is associated with any negative side effects is a matter of debate. Brodeur272 reviewed the
literature and concluded that the investigations were very limited
and inconclusive. It appears that habitual joint cracking is not
associated with an increase in cartilage damage or osteoarthritic
changes, although one study did note an increase in joint swelling
and loss of grip strength in habitual joint crackers.
There are other potential causes of noises associated with various forms of manual therapy that are not a product of cavitation. With the development of cross-linkages in traumatized soft
tissues, a manual procedure can break them apart, theoretically
producing an audible tearing sound. With some mobilizing or
manipulating procedures, the necessary movements of the parts
can cause muscle tendons to move over bony protuberances, producing an audible snapping sound. Bony outgrowths can produce
impingement that, with movements of the involved parts, can
produce an audible clunking sound. Degenerative joint disease
can produce crepitus on joint movement, producing an audible
crackling sound.
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| Chiropractic Technique
Articular cartilage
B
Fibrous cap of
meniscoid
Articular capsule
Impinged position
Reduced: hard edge remaining
remodels with time
Reduced
Fibroadipose tissue
cell base
C
A
Normal position
Figure 4-14â•… Position and postulated incarceration of synovial joint meniscoids. A, Diagram of the structural components of a meniscoid in a
lumbar facet joint. B, Meniscoid entrapment in cervical facet joints restricting extension and flexion movements. C, Entrapment of meniscoids is
postulated to produce deformation of the articular cartilage surface; after reduction and over time the articular cartilage will remodel. (A modified from
Dupuis,186. C modified from Lewit98.)
Joint Fixation
Joint fixation implies a partial or complete restriction in joint
movement. The restriction may be in one or more directions, and
when used in chiropractic circles, it typically refers to a partial loss
of joint movement (hypomobility), not a complete loss of movement. Several theories concerning the cause of joint fixation have
been advanced. Derangements of the posterior joints, intercapsular adhesions, and intradiscal derangement have been proposed as
interarticular sources; segmental muscle spasm and periarticular
soft tissue fibrosis and shortening have been proposed as extraarticular sources.
Interarticular Adhesions
Interarticular adhesions refer to the hypothesis that joint fixation
or hypomobility may be a product of adhesions that have developed between the articular surfaces of the Z joints.285 This process
is speculated to result from joint injury, inflammation, or immobilization.241,247,249,254,286-289 Joint injury or irritation leading to chronic
inflammation and joint effusion may induce synovial tissue hyperplasia, invasion of fibrous connective tissue, and consequent interarticular adhesions.56,57,247 In addition, Gillet289 has suggested that
prolonged joint immobilization secondary to periarticular ligamentous shortening may eventually lead to fibrous adhesion formation
between joint surfaces. Adjustive therapy is postulated to induce
gaping of the involved joints breaking the adhesions between joint
surfaces and improving or restoring joint mobility.
Interarticular Block
The term interarticular block refers to a reduction (blockage) of
joint movement that is a product of some derangement within
the synovial joint, internal to the joint capsule. Entrapment of
the interapophysary meniscus within the posterior spinal joints
has been hypothesized as a cause of episodic acute back pain and
joint locking.10,290-295 The menisci are purportedly drawn into a
position between the joint margins during poorly coordinated spinal
movements or by sustained stressful postures (Figure 4-14, A).
With resumption of normal postures, pain results from impaction
A
Articular cartilage
Meniscoid
B
Figure 4-15â•… Techniques producing joint distraction have the poten-
tial to produce cavitation and reduce entrapment or extrapment of meniscoids. A, Technique applied to induce flexion, lateral flexion, and rotation
in the left lumbar facets. B, Separation and expulsion of entrapped
meniscoid.
of the menisci or traction of the articular capsule, inducing reactive muscle spasm and joint locking. The development of a painful
myofascial cycle is initiated as prolonged muscle contraction leads
to muscle fatigue, ischemia, and more pain. If spasm and locking persist, the articular cartilage may mold around the capsular
meniscus, causing it to become more rigidly incarcerated within
the joint (see Figure 4-14, B and C).294–296
To interrupt the cycle of pain, muscle cramping, and joint
locking, distractive adjustments have been presented as a viable
therapy capable of inducing joint separation, cavitation, and liberation of the entrapped meniscoid (Figure 4-15).
Bogduk and Engel297 question the plausibility of meniscus
entrapment as a source of acute joint locking and make a compelling case for meniscoid extrapment. They contend that meniscoid entrapment would require the meniscus to have a firm
apex strongly bound to the capsule by connective tissue. Their
Chapter 4â•… Principles of Adjustive Technique |
morphologic studies did not confirm such an anatomic entity.
They did imply, however, that a piece of meniscus torn and dislodged from its base could form a loose body in the joint, capable
of acting as a source of back pain amenable to manipulation.
Bogduk and Jull298 favor instead the theory that the meniscoids
become extrapped rather than entrapped. In their model of dysfunction, as the joint goes into flexion, the meniscoid is drawn
out of the joint, and on return into extension, the meniscoid fails
to properly reenter the joint cavity. Instead it lodges against the
edge of the articular cartilage, where it buckles, serving as a spaceoccupying lesion that causes pain by distending the joint capsule (Figure 4-16).297 Manipulation that produces passive flexion
should reduce the impaction, and rotation should gap the joint,
encouraging the meniscoid to reenter the joint cavity.298
Other theories of interarticular soft tissue entrapment suggest
that impingement of synovial folds or hyperplastic synovial tissue
are additional sources of acute back pain and locking.299–302
Bony locking of the posterior joints at the end-range of spinal
motion have also been proposed. It is suggested that the developmental incongruencies and ridges in joint surface anatomy, combined with the complex coupled movements of the spine, may
lead to excessive joint gapping at the extremes of movement,
which may in turn lead to bony locking as the surfaces reapproximate.300 In both circumstances, distractive adjustive therapy has
the potential to reduce the locking.
Interdiscal Block
Interdiscal block refers to internal derangement of the disc that
leads to alterations or reductions in normal motion of the spinal
motion segments. The mechanical derangements of the IVD
that may lead to joint dysfunction are postulated to result from
pathophysiologic changes associated with aging, degenerative disc
disease, and trauma. Farfan303 has proposed a model of progressive disc derangement based on repetitive rotational stress to the
motion segment. He postulates that repetitive torsional loads of
sufficient number and duration may, over time, lead to a fatigue
injury in the outer annular fibers. The process begins with circumferential distortion and separation in the outer annular fibers,
followed by progression to radial fissuring and outward migration
of nuclear material. The rate of fatigue and injury depends on the
duration and magnitude of the force applied. In the individual
with disrupted segmental biomechanics, the process is potentially
113
accelerated as an altered axis of movement leads to increased rotational strain on the IVD.
As presented earlier, the significance of torsional stress on the
IVD, especially without coupled flexion, has been questioned. The
sagittal orientation of the lumbar facets and the protective rotational barrier they provide bring into question the susceptibility
of the lumbar discs to rotational torsion.165,169,170,303,304 Regardless
of the mechanism or process, there is little doubt that internal disc
derangement can lead to episodic or prolonged painful alterations
or reductions in spinal movement.
Further complicating discal injury and internal disc disruption
are the likely inflammatory and potential autoimmune reactions
triggered by cellular disruption. Naylor305 has suggested that a discal injury with its associated connective tissue repair and vascularization is sufficient to create an antibody-antigen inflammatory
reaction by exposing proteins of the nuclear matrix. The net effect
is diminished protein polysaccharide content of the nucleus pulposus, loss of fluid content, and progression and acceleration of
nuclear degeneration. As the nucleus atrophies, the disc becomes
more susceptible to loading, and additional tractional forces may
be transferred to the annulus, inducing mechanically based pain as
the intact outer fibers are excessively stretched.140
Interwoven into the natural history of degenerative disc disease
may be episodes of acute mechanical back pain and joint locking.
Others24,29,12,305-309 have postulated that incidents of blockage may
occur during movements of trunk flexion as nuclear fragments
become displaced and lodged along incomplete radial fissures in
the outer fibers of the posterior annulus (interdiscal block) (Figure
4-17). Consequently, when extension is attempted, the displaced
fragment cannot return to its central position and becomes compressed. The compressed fragment produces radial tension on the
posterior annulus, causing pain and potential local muscle guarding
and joint locking. Cyriax308 proposes that these lesions may induce
tension on the dura mater, inducing low back pain (LBP) and muscle
splinting. Once local pain and muscle spasm are initiated, a selfperpetuating cycle of pain, cramping, and joint locking may
result. Adjustive therapy has been proposed as a viable treatment
for interrupting this cycle of acute back pain and joint locking. In
addition to the distractive effect on the posterior joints, adjustive
therapy is thought to have a potential direct effect on the IVD,
either by directing the fragmented nuclear material back toward a
more central position or by forcing the nuclear fragment toward
a less mechanically and neurologically insulting position between
the lamellae of the annulus.309
B
A
D
C
Figure 4-16â•… Theory of meniscoid extrapment. A, On flexion, the
inferior articular process of a zygapophyseal joint moves upward, taking a
meniscoid with it. B, On attempted extension, the inferior articular process
returns toward its neutral position, but the meniscoid, instead of reentering
the joint cavity, buckles against the edge of the articular cartilage, forming a
space-occupying lesion under the capsule. C, Manipulation gaps the joint,
allowing the meniscoid to return to its neutral resting position (D).
Normal
Interdiscal block
Figure 4-17â•… Fragments of nuclear material migrate in annular
defects, creating an interdiscal block.
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| Chiropractic Technique
Two separate mechanical concepts have been proposed as
models for how this might occur. The Gonstead adjustive technique has presented a model using adjustments to close down the
side of nuclear migration (slippage) and force the material back
toward the center (Figure 4-18).310 The second concept, presented
by Sandoz,24 proposes a model in which distractive side posture
adjustments combine disc distraction with rotation to induce helicoid traction and draw the herniated nuclear material back toward
the center (Figure 4-19).
Internal derangement of the disc without associated NR dysfunction is difficult to conclusively differentiate from other
mechanical disorders of the motion segment. Repetitive end-range
loading and centralization of the patient’s symptoms, especially
in the presence of leg pain, has demonstrated value in helping
Figure 4-18â•… Techniques designed to close the side of nuclear migration (open wedge) are performed to force nuclear material toward the
center of the disc.
clinically diagnoses this condition,311 but consensus has not been
reached on the clinical criteria and standard of care for definitively
establishing this disorder. Consequently, clinical research evaluating the effects of chiropractic HVLA adjustive treatment on IVD
syndromes has focused primarily on biomechanical studies investigating chiropractic management of disc protrusion or herniation
confirmed by imaging.
Levernieux312 noted reduction in disc herniation with axial traction, and Matthews and Yates313 reported epidurographic reductions in disc herniations with manipulation. In contrast, Christman,
Mittnacht, and Snook314 reported a notable improvement in 51%
of their patients treated with manipulation, but they reported no
change in disc hernia as measured with myelography. Sandoz24
concluded that the contradictory findings between these two studies can be accounted for by the fact that epidurography may measure smaller derangements of the disc, whereas myelography reveals
only larger protrusions that are less amenable to manipulative care.
It is doubtful that manipulation can reduce an external protrusion,
but Sandoz24 has suggested that manipulation may have a role to
play in shifting the herniation away from the NR, minimizing the
mechanical conflict and associated inflammation. In such circumstances, treatment is expected to be more protracted.24
Well-designed and well-conducted clinical trials on HVLA
adjustive therapy for disc herniation and associated radiculopathy (sciatica) are very limited. Clinical trials, uncontrolled
descriptive studies, and case reports on the manipulative treatment of lumbar disc herniations are few, but they do indicate
that this patient population may benefit from chiropractic manual therapy.24,304,314-324
The incidence of complications arising from the manipulative
treatment of disc herniation patients is extremely low. However,
this procedure may carry some very minimal risk. Accordingly,
modifications of side posture manipulative techniques have been
suggested in the treatment of patients with marked disc herniations. To minimize the risk of further annular injury, side posture
adjusting or mobilization postures, which minimize excessive lumbar flexion and compression, have been proposed.304 Procedures
and positions that increase the patient’s leg pain are assumed to be
more stressful to the annular fibers and are to be avoided. Those
that reduce or centralize back pain while decreasing the patient’s
leg pain are presented as potentially the safest and most effective.
Disc herniation patients suffering progressive neurologic deficits
or midline herniations with an associated CES should not be considered for manipulation.325–328
Periarticular Fibrosis and Adhesions
Figure 4-19â•… Techniques using distraction combined with rotation induce a helicoid traction that is intended to draw nuclear material
toward the center of the disc.
As mentioned previously, acute or repetitive trauma may lead to
articular soft tissue injury. In the process of fibrotic repair, adhesions and contractures may develop, resulting in joint hypomobility. Distractive adjustments are advanced as procedures capable of
effectively treating these derangements by stretching the affected
tissue, breaking adhesions, restoring mobility, and normalizing
mechanoreceptive and proprioceptive input.30,237-239
It is further postulated that manipulation may sever the adhesive
bonds, stretch tissue, and promote mobility without triggering an
inflammatory reaction and recurrence of fibrosis. However, when
articular or nonarticular soft tissue contractures are encountered,
Chapter 4â•… Principles of Adjustive Technique |
incorporation of procedures that minimize inflammation and
maintain mobility should be considered. Viscoelastic structures
are more amenable to elongation and deformation if they are first
warmed and then stretched for sustained periods.329 Therefore,
the application of moist heat, ultrasound, and other warming
therapies might be considered before applying sustained manual
traction or home-care stretching exercises.
Joint Instability
Although emphasis has been placed on the adjustive treatment of
mechanical disorders resulting from joint hypomobility, manipulative therapy also may have a role in the treatment of clinical joint
instability. Clinical joint instability can be defined as a painful disorder of the spine resulting from poor segmental motor control or
a loss of stiffness in the controlling soft tissues that leads to a loss
of motion segment equilibrium and an increase in abnormal translational or angular movements.330,331 Common proposed causes
of joint instability include acute trauma, repetitive-use injuries,
compensation for adjacent motion segment hypomobility,332 ineffective neural control, degenerative disc disease, and muscle weakness or poor endurance.333 Clinical joint instability is not to be
confused with gross orthopedic instability resulting from marked
degeneration, traumatic fracture, or dislocation.
Joint instability may predispose the patient to recurring
episodes of acute joint locking and may be seen more frequently
in individuals who have some degree of hypermobility that is
a result of advanced training in athletics such as gymnastics or
ballet dancing.332 Adjustive therapy applied in this condition
is not intended to restore lost movement but rather to reduce
the episodic pain, temporary joint locking, joint subluxation,
and muscle spasm that are commonly encountered in patients
with unstable spinal joints. Adjustive therapy delivered in these
circumstances is considered to be palliative. It should not be
applied during an extended period, and it should be incorporated with stabilization therapy, appropriate exercise, and lifestyle
modification.332,333
Neurobiologic Hypothesis
Analgesic Hypothesis
The reduction of pain and disability from spinal manipulation is well recognized and clinically documented.147,194,199,334-340
“Numerous studies suggest that SM alters central processing of
noxious stimuli because pain tolerance or pain threshold levels can
increase after manipulation.”261 The mechanisms by which manipulation inhibits pain, however, are matters of speculation and still
under investigation. Proposed hypotheses have suggested that
manipulation has the potential to remove the source of mechanical
pain and inflammation or induce stimulus-produced analgesia.
The case for decreasing pain by removing its mechanical source
is empiric and deductive. The pain associated with mechanical
disorders of the musculoskeletal system is a product of physical
deformation, inflammation, or both.341 It is reasoned that
manual therapy effective at reversing or mitigating underlying
structural and functional derangements will remove the source of
pain and the associated pain-producing agents as structures are
returned to normal function.
115
The argument for stimulus-produced analgesia is bolstered by
experimental evidence that suggests that chiropractic adjustments
induce sufficient force to simultaneously activate both superficial
and deep somatic mechanoreceptors, proprioceptors, and nocicep�
tors. The effect of this stimulation is a strong afferent segmental
barrage of spinal cord sensory neurons, capable of altering the pattern of afferent input to the central nervous system and inhibiting
the central transmission of pain (Figure 4-20).341-345
Gillette342 suggests that spinal adjustments may initiate both
a short-lived phasic response triggered by stimulation of superficial and deep mechanoreceptors, and a longer-lived tonic response
triggered by noxious-level stimulation of nociceptive receptors.
The phasic response is hypothesized to initiate a local gating
effect, but pain inhibition terminates with cessation of therapy.
The tonic response initiated by noxious levels of mechanical stimulation is more powerful and capable of outlasting the duration of
applied therapy.344
Adjustments that induce joint cavitation and capsular distraction may be a source of nociceptive stimulation capable of initiating relatively long-lasting pain inhibition. This concept supports
the premise that the slight discomfort that may be associated
with adjustments is causally associated with a positive therapeutic effect.334
The potential for spinal adjustments to act directly on the
pain system opens up the possibility that manipulation may have
the ability to diminish persistent pain that is neuropathic in origin.345 Chronic neuropathic pain may result from plastic changes
and central sensitization of the nervous system. Central sensitization refers to plastic changes in the nervous system that result
from persistent amplification of nociceptive synaptic transmission. This can result in the persistence of pain states even after
the offending peripenial pathologic injury and inflammation
have resolved.344
The short-term bursts of proprioceptive and nociceptive input
associated with adjustments, much like transcutaneous electrical
nerve stimulation and acupuncture, have also been theorized to
increase the levels of neurochemical pain inhibitors.337 Both a local
release of enkephalins, initiated by stimulation of the neurons of
substantia gelatinosa, and a systemic increase in plasma and cerebrospinal fluid endorphin levels, initiated by simulation of the
hypothalamic pituitary axis, have been proposed. Both substances
act as endogenous opioid pain inhibitors and may play a role in
the analgesic effects of adjustments.
Doctor reassurance and the laying-on of hands may also impart
a direct analgesic effect, which must be factored into the equation
when calculating the effects of adjustments and manual therapy.
The contact established during a skilled evaluation of the soft tissues indicates the doctor’s sense of concern and skill. Paris331 states
that with the addition of a skilled evaluation involving palpation
for soft tissue changes and altered joint mechanics, the patient
becomes convinced of the clinician’s interest, concern, and manual
skills. If the examination is followed by treatment and an adjustive
cavitation (crack), further positive placebo effects may be registered. The astute clinician accepts and reinforces this phenomenon if it influences the patient’s recovery. This does not excuse
misrepresentation or irresponsible exaggeration of the therapeutic
effect.
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| Chiropractic Technique
Posterolateral
quadrant
white matter
Supersegmental descending
analgesic system
A mechanoreceptors
Inhibitory
interneuron
Pain
Anterolateral
quadrant
white matter
A and C nociceptors
Pain transmission cell
Figure 4-20â•… Diagram suggesting the mechanism by which a high-velocity chiropractic adjustment inhibits the central transmission of pain through
activation of mechanoreceptors and nociceptors. (Modified from Gillette, Cassidy JD, Lopes AA, Yong-Hing K: The immediate effect of manipulation
versus mobilization on pain and range of motion in the cervical spine: A randomized controlled trial, J Manipulative Physiol Ther 15:570, 1992.)
Muscle Spasm (Hypertonicity)
Numerous authors have presented the potential causative role of
hypertonic muscles in the development of joint dysfunction and spinal pain.24,238,289,292,346-349 The concept that restricted joint movement
may result in increased segmental muscle tone or spasm is supported
by the knowledge that muscles not only impart movement but also
impede movement. Joint movement depends on a balance between
its agonist and antagonists. If this balance is lost and antagonistic
muscles are unable to elongate because of involuntary hypertonicity,
the joint may be restricted in its range or quality of movement.
Increased resting muscle tone or spasm may be initiated by
direct provocation or injury to myofascial structures or indirectly by stimulation or injury to associated articular structures.
Direct overstretching and tearing of muscle lead to stimulation
of myofascial nociceptors and protective muscle splinting. The
intersegmental muscles of the spine may be especially vulnerable
to incidents of minor mechanical stress and overstretching. They
are not under voluntary control. They act primarily to stabilize
and integrate segmental movements in response to global movements of the trunk. As a result, they may be especially vulnerable
to unguarded movements and the induction of reactive splinting.
Korr346 suggests that unguarded and uncoordinated movements may approximate the short segmental muscles of the back
and reduce annulospiral receptor activity in the muscle spindle
complex and produce muscle spasm. Maigne291 envisions a similar
lesion (articular strain), but speculates that it results from �abnormal
sustained postures or poorly judged movements that induce minor
intersegmental muscle overstretching and cramping. Both speculate that segmental muscle spasm, once initiated in the back, may
be hard to arrest. Contracted segmental muscles of the back, unlike
the voluntary appendicular muscles, are not easily stretched by the
contraction of antagonistic muscle groups. As a result, this condition may not be inhibited by active stretching and therefore may
be less likely to be self-limiting.291 Research published in 2000
demonstrated that muscle spasm reduced the ability of paraspinal
muscle stimulation to evoke cerebral potentials.350 “Spinal manipulation reversed these effects, reducing muscle spasm and restoring
the magnitude of the evoked cerebral potentials.”261
Myofascial Cycle
A central complicating feature of many of the internal and external derangements of the motion segment is the induction of a self�
perpetuating myofascial cycle of pain and muscle spasm. The articular
soft tissues are richly innervated with mechanoreceptors and nociceptors, and traction or injury to these structures may lead to the initiation of local muscle splinting. With time, the continued muscle
contraction may lead to further muscle fatigue, ischemia, pain, and
maintenance of muscle spasm and joint locking (Figure 4-21).
High-velocity adjustments are suggested as treatments that
may be effective in interrupting this cycle. Several theories exist
as to the mechanism by which adjustments relieve muscle spasm.
Both are speculated to induce a reflex response in muscle—one
Chapter 4â•… Principles of Adjustive Technique |
Uncoordinated movements
Chronic postural stress
Articular strain
Pain
Retained metabolites
Edema (inflammation)
Muscle spasm
Vasoconstriction
ischemia
Joint dysfunction
Figure 4-21â•… The self-perpetuating cycle of myofascial pain and
�muscle spasm.
through direct action on muscle and the other reflexly through
joint distraction (cavitation). The direct muscle model346 speculates that quick traction and excitation of the Golgi tendon organ
(GTO), located in the muscle tendon junction, act as brakes to
limit excessive joint movement and possible injury by inhibiting
motor activity. The concept is that adjustments induce a strong
stretch on the muscle tendon complex, activate the GTO, and
induce reflex muscle relaxation (autogenic inhibition). Although
this model seems reasonable, evidence suggests that the GTO has
a less profound effect than initially envisioned. Watts and associates349 found that stimulation of the GTO produces a very meager inhibitory effect on motor neuron activity. This information
implies that the GTO plays a more minor role in the inhibition of
muscle spasm than initially proposed and brings into question its
relationship to postadjustment muscle relaxation.
In contrast, stimulation of articular low- and high-threshold
mechanoreceptors and nociceptors has demonstrated a notable
inhibitory effect on segmental motor activity.342 Mechanoreceptors
and nociceptors are also widely embedded in articular soft tissues,
muscle, and skin. High-velocity adjustments induce enough force
to stimulate these structures and induce a burst of somatic afferent
receptor activity.281,342 Based on this information, it seems reasonable to assume that joint and soft tissue mechanoreceptors and
nociceptors have the potential to play a material role in the inhibition of muscle spasm and the interruption of painful myofascial
cycles and joint locking.
Clinical investigations on the effects of spinal manipulation
on muscle activity are very limited. Investigations have centered
on the effects of manipulation during and after the application
of manipulation. Using surface electromyograph (EMG), Herzog
and others351–353 investigated the immediate effects of thoracic
SMT on paraspinal muscle activity. They applied prone unilateral
quick (HVLA) and slow (3- to 4-second) “manipulations” to the
117
�
thoracic
transverse processes. Both procedures consistently induced
momentary increased muscle activity during their application.
The high-velocity manipulations were associated with a fast, burstlike EMG signal, and the slow manipulation with a gradual increase
in EMG activity. Cavitations induced during the application of the
slowly applied manipulation were not associated with increased
EMG activity, leading the researchers to speculate that cavitation alone is not sufficient to induce a reflex muscular response.
The myoelectric response recorded during thoracic adjustments
did conflict with the application of the adjustive forces. In contrast, Triano and Schultz161 were unable to record any significant
myoelectric activity or muscular responses with the application of
HVLA SP lumbar-adjusting procedures.
Investigations into more prolonged effects on resisting muscle activity, although very limited, have shown reductions in
paraspinal muscle activity and imbalance with full-spine adjusting
procedures.352,353
Nerve Root Compression
Chiropractic, osteopathy, and manual medicine has envisioned
manual therapy affecting not only somatic disorders, but also visceral disorders through neurologic means.17 The early paradigm
presented in chiropractic stressed a model of altered NR function as the basis for secondary somatic or visceral dysfunction. It
was theorized that subluxations induce structural alteration of the
intervertebral foramina, leading to compression of the contained
neurovascular structures and altered function of the NR as electrical transmission or axoplasmic flow is impaired. The postulated net
result of this process (nerve interference) was dysfunction or disease in the somatic and visceral structures supplied by the affected
NR.17,354-359 The subluxation-induced narrowed intervertebral foramen (IVF) was hypothesized to induce NR dysfunction through
direct bony compression (pinched-hose model) or indirectly by
increasing pressure around the NR and its vascular structures.
In 1973, Crelin360 challenged the anatomic plausibility of subluxated motion segments producing NR compression. His anatomic dissections and measurements, made at the lateral borders
of the IVF, demonstrated a minimum of 4â•›mm of space around
the NR. He concluded that the space was more than adequate
and that the NR was not anatomically vulnerable to compression.
More recently in 1994, Giles361 revisited the issue of NR vulnerability but at a different anatomic site. His measurements were
taken at the interpedicular zone and demonstrated an average of
only 0.4 to 0.8╛mm of space around the NR and the NR gang�
lion. He concluded that the NR was anatomically vulnerable, but
at the interpedicular zone, not at the lateral borders of the IVF.
Furthermore, “dorsal roots and dorsal root ganglia [DRG] are
more susceptible to the effects of mechanical compression than
are axons of peripheral nerves because impaired or altered function is produced at substantially lower pressures.”361
A potential site of anatomic vulnerability does not, by any
means, validate chiropractic models of subluxation-induced NR
dysfunction. The plausibility of uncomplicated subluxations commonly inducing NR compression still seems unlikely.355-360 It does,
however, raise an interesting issue about the potential for spinal
motion segment dysfunction to contribute to NR compression
when it is associated with other compromising joint patholo-
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| Chiropractic Technique
gies.300,361,362 Disc herniation and exposure of the NR to discal
material increase spontaneous nerve activity and the mechanical
sensitivity of the NR and possible mechanical hyperalgesia. Spinal
NRs already compromised by disc herniation, degenerative joint
and disc disease, or central or lateral stenosis and the associated
inflammation may become more serious when associated with dysfunction that fixes the joint in a more compressive and compromising position. In such circumstances, adjustive therapy that reduces
a position of fixed subluxation and root irritation may have an
effect on reducing NR traction, compression, or inflammation.
Reflex Dysfunction
Beginning with the work of Homewood,358 the profession has
gradually moved away from reliance on NR compression and
toward a more dynamic model of subluxation-induced neurodysfunction. As presented in Chapter 3, the reflex paradigm presents a model in which somatic dysfunction or joint dysfunction
induces persistent nociceptive and altered proprioceptive input.
This persistent afferent input triggers a segmental cord response,
which in turn induces the development of pathologic somatosomatic or somatovisceral disease reflexes357-359,363-368 (Figure 4-22). If
these reflexes persist, they are hypothesized to induce altered function in segmentally supplied somatic or visceral structures.
Chiropractic adjustive therapy has the potential for arresting
both the local and the distant somatic and visceral effects by normalizing joint mechanics and terminating the altered neurogenic
reflexes associated with joint dysfunction. For example, a patient
with a strained posterior joint capsule accompanied by reflex muscle spasm may have nociceptive bombardment of the spinal cord.
If the nociceptive bombardment is of sufficient strength and duration, it may cause segmental facilitation. The spinal adjustment
may reduce the strain on the joint capsule and reduce muscle
spasm that stops nociception from these tissues into the spinal
cord. At the same time, adjustments stimulate many different
types of mechanoreceptors. The result is a reduction of a harmful somatosomatic and potential somatoautonomic reflex. This
model has become the focus of more attention and investigation as
4
Visceral
afferent
2 1
2
Afferent
from joint
Efferent
blood vessels
3
chiropractors search for an explanation to the physiologic effects
that they have clinically observed to be associated with spinal adjustive therapy. This relationship is not consistent, and the frequency
of response is undetermined, but the anecdotal and empiric experiences of the profession are significant enough to warrant serious
further investigation.
An additional model of subluxation-induced neurodysfunction focuses attention on the potential direct mechanical irritation
of the autonomic nervous system. The paradigm for irritation of
sympathetic structures is based on the anatomic proximity and
vulnerability of the posterior chain ganglion, between T1 and L2,
to the soma of the posterior chest wall and costovertebral joints.
Altered spinal and costovertebral mechanics are hypothesized to
mechanically irritate the sympathetic ganglia and to induce segmental sympathetic hypertonia.368 The target organs within the
segmental distribution then theoretically become susceptible to
altered autonomic regulation and function as a result of altered
sympathetic function.
In contrast to the sympathetic chain, the parasympathetic system, with its origins in the brain, brainstem, and sacral segments
of the spinal cord, does not have anatomic proximity to the spinal
joints. Models of mechanically induced dysfunction of the parasympathetic system propose dysfunction in cranial, cervical, and
pelvic mechanics as potential sources of entrapment or tethering of
the parasympathetic fibers. Altered cervical, cranial, or craniosacral
mechanics are theorized to induce traction of dural attachments and
the cranial nerves as they exit through the dura and skull foramina. The treatment goal in mechanically induced autonomic dysfunction is to identify the sites of joint dysfunction and implement
appropriate manual therapy to balance membranous tension.369
From the discussion of spinal dysfunction and its potential
neurobiologic effects on health, it must be remembered that
spinal dysfunction and pain may be the product of, not the cause
of, somatic or visceral dysfunction or disease.370 Spinal pain and
dysfunction may be secondary to a disorder that needs direct treatment. Manual therapy may be a fitting component of appropriate care, but would be inadequate as the singular treatment. The
patient with caffeine-induced gastritis who develops secondary
midback pain and dysfunction (viscerosomatic) should not receive
manual therapy without also being counseled to discontinue
ingestion of caffeinated beverages. The spine is a common site of
referred pain, and when a patient with a suspected mechanical or
traumatic disorder does not respond as anticipated, the possibility
of other somatic or visceral disease should be considered.
Neuroimmunology
Visceral
efferent
Efferent
to muscle
Figure 4-22â•… Afferent and efferent pathways from and to the viscera
and somatic structures that can produce (1) somatosomatic, (2) somatovisceral, (3) viscerosomatic, and (4) viscerovisceral reflex phenomena.
(Modified from Schmidt,188.)
An interaction exists between the function of the central nervous
system and the body’s immunity that lends support to the chiropractic hypothesis that neural dysfunction is stressful to the body locally
and globally. Moreover, with the resultant lowered tissue resistance,
modifications to the nonspecific and specific immune responses
occur, as well as altered trophic function of the involved nerves. This
relationship has been termed the neurodystrophic hypothesis.
Selye371-373 demonstrated neuroendocrine-immune connections
in animal experiments and clinical investigations. Physiologic,
psychologic, psychosomatic, and sociologic components compose
the stress response. From studies of overstressed animals, Selye
Chapter 4â•… Principles of Adjustive Technique |
observed nonspecific changes that he labeled the general adaptive
syndrome. He also observed very specific responses that depended
on the stressor and on the part of the animal involved, which he
termed local adaptive syndrome. Furthermore, he established a stress
index comprising major pathologic results of overstress, including
enlargement of the adrenal cortex, atrophy of lymphatic tissues, and
bleeding ulcers. Selye also felt that long-term stress would lead to
diseases of adaptation, including cardiovascular disease, high blood
pressure, connective tissue disease, stomach ulcers, and headaches.
Stressors can produce profound health consequences.374
Theorists propose that stressful events trigger cognitive and affective responses that, in turn, induce sympathetic nervous system
and endocrine changes, and these ultimately impair immune
function.375-379 Stressful events cannot influence immune function directly. Instead, stress is thought to affect immune function
through central nervous system control of the hypothalamicpituitary-adrenal (HPA) axis and sympathetic-adrenal-medullary axis.377,380-383 Stressors produce reliable immune changes.374
Segerstrom and Miller384 analyzed different types of stressors separately and found that the immunologic effect of stressors depends
on their duration.
However, because all individuals do not develop the same syndrome with the same stressor, Mason385 suggested that emotional
stimuli under the influence of internal (genetics, past experiences,
age, and sex) or external (drugs, diet, and hormone use) conditioning are reflected in the responses of the endocrine, autonomic,
and musculoskeletal systems385 (Figure 4-23).
Stein, Schiavi, and Camerino386 convincingly demonstrated
psychosocial and neural influences on the immune system. They
showed that the hypothalamus has a direct effect on the humeral
immune response, explaining how psychosocial factors can modify host resistance to infection. Moreover, Hess387 produced sympathetic and parasympathetic responses by stimulating different
parts of the hypothalamus. The sympathetic response (ergotropic response) is characteristic of the fight-or-flight mechanism,
whereas the parasympathetic response (trophotropic response)
produces relaxation that promotes a restorative process. Table 4-2
lists the characteristics and physiologic responses of the ergotropic
and trophotropic states.
THE COMMON STRESSORS AND THEIR EFFECTS
External input
(drugs, diet, hormone use)
Internal input
(genetics, past
experience, age, sex)
Central nervous
system
Endocrine
system
Musculoskeletal
system
Autonomic nervous
system
Figure 4-23â•… Internal and external conditioning can affect emotional
stimuli, resulting in autonomic, endocrine, or musculoskeletal changes.
Table 4-2
119
haracteristics of the Ergotropic
C
and Trophotropic Responses
Ergotropic Responses
Trophotropic Responses
Primarily sympathetic
Excitement, arousal,
action
Movement of body or
parts
Increased heart rate,
blood pressure,
respiratory rate
Increased blood sugar
Primarily parasympathetic
Relaxation
Increased muscle tension
Increased dioxide
consumption
Increased carbon dioxide
elimination
Pupil dilation
Energy conservation
Decreased heart rate,
blood pressure,
respiratory rate
Increased gastrointestinal
function
Decreased muscle tension
Decreased dioxide
consumption
Decreased carbon dioxide
elimination
Pupil constriction
The three classically separated areas of neuroscience, endocrinology, and immunology, with their various organs—the brain;
the glands; and the spleen, bone marrow, and lymph nodes,
respectively—are actually joined to one other in a multidirectional
network of communication, linked by information carriers known
as neuropeptides. The field of study is called psychoneuroimmunology (PNI). PNI is a scientifically solid field of study, grounded in
well-designed experiments and in the resolute tenets of behaviorism.388 The first components of the process of linking the systems
of the body together, and ultimately the body and mind, are the
receptors found on the surface of the cells in the body and brain.
Almost every peptide receptor, not just opiate receptors, could be
found in this spinal cord site that filters all incoming bodily sensations. It has also been found that in virtually all locations at which
information from any of the five senses enters the nervous system
there is a high concentration of neuropeptide receptors. These
regions are called nodal points.388
Today’s health care provider should recognize the interconnectedness of all aspects of human emotion and physiology. The skin,
the spinal cord, and the organs are all nodal points of entry into
the psychosomatic network. Health care providers that incorporate touching and movement in their treatment of patients affect
them all.
Leach389 points out that there is a paucity of studies that directly
link vertebral lesions with immunologic competence, although his
review of the literature suggests that such a connection is possible.
Fidelibus,390 after conducting a recent review of the literature, concluded that the concepts of neuroimmunomodulation, somatosympathetic reflex, and spinal fixation provide a theoretic basis for
using spinal manipulation in the management of certain disorders
involving the immune system, including asthma, allergic rhinitis,
and the common cold. He further postulates that musculoskeletal dysfunction can result in immune dysfunction and that, by
removing the musculoskeletal dysfunction, spinal manipulation
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| Chiropractic Technique
can affect the immune dysfunction. As mentioned previously, chiropractic manipulation did not have a positive outcome in treating childhood asthma in a population of children who were less
than optimally responsive to medication.216
Two studies on infantile colic233,391 indicate that chiropractic
treatment results in a reduction of the daily length and number
of colic periods. Klougart and associates234 found that 94% of
the infants studied were helped by chiropractic treatment within
14 days from the start of treatment. Wiberg, Nordsteen, and
Nilsson391 compared spinal manipulation with dimethicone medication. The infants in the chiropractic group exhibited a 67%
reduction of daily hours of colic, whereas the dimethicone group
had a 38% reduction. However, a 2001 randomized placebo controlled study that blinded the parents from the therapy found no
difference between placebo and spinal manipulation in the treatment of infantile colic.235
Vernon and colleagues337 reported a slight, but statistically significant, increase in B-endorphin levels in asymptomatic males
after cervical manipulation, whereas Sanders et al392 and Christian,
Stanton, and Sissons393 found no change in B-endorphin levels in
either symptomatic or asymptomatic male study participants after
chiropractic manipulation.
Whelan and associates394 examined 30 asymptomatic male chiropractic students in a randomized clinical trial to determine the
effect of HVLA cervical manipulation on salivary cortisol secretion. They found no effect of chiropractic manipulation on salivary cortisol and concluded that in asymptomatic subjects familiar
with chiropractic manipulation, neither the sham nor cervical
manipulation induces a state of anxiety sufficient to disrupt the
homeostatic mechanisms and activate the HPA axis.
Teodorczyk-Injeyan, Injeyan, and Ruegg395 report that SMT in
asymptomatic subjects down-regulates production of the inflammatory cytokines tumor necrosis factor–α and interleukin
1β (IL-1β). They also determined that this change in cytokine
production was unrelated to serum substance P levels.
The work of Brennan and others396-403 remains the only
extended line of investigation into the effect of chiropractic SM
and immune function. They reported that a single manipulation
in the thoracic or lumbar spine produced a short-term priming
of the polymorphonuclear cell response to an in vitro particulate
challenge. They observed an enhanced chemiluminescent respiratory burst in both asymptomatic and symptomatic study participants.396,398,403 This enhanced polymorphonuclear cell activity was
associated with slight, but statistically significant, rise in plasma
substance P. Further investigation suggested that this systemic
effect depends on both the applied force and vertebral level.398,403
In follow-up, Kokjohn and co-workers404 hypothesized that the
force applied to the thoracic spine by manipulation is sufficient
to result in increased plasma levels of substance P, which may
prime circulating phagocytic cells for enhanced respiratory burst.
However, whether the effect is significant in fighting infection has
not been determined, and the exact mechanism whereby manipulation affects phagocytic cells remains speculative, because significant levels of plasma substance P were not determined.
The available studies suggest mechanisms by which spinal influences may mediate a clinically significant effect on immune function, but few studies have directly examined those mechanisms,
and the evidence to date is conflicting. Consequently, there
are clearly both plausible mechanisms to explore and clinical practice–driven justification for additional basic science studies in this
area.261
Circulatory Hypothesis
Beneficial vascular responses to adjustive therapy are theorized to
result as a product of stimulation of the autonomic nervous system or through improved function of the musculoskeletal system.
Experimental and clinical evidence suggests the importance of an
adequate blood supply for optimal function.405 It was observed
long ago that vasoconstriction resulting from sympathetic hyperactivity reduces blood volume substantially, posing a threat of relative ischemia in the area involved.406 Disturbances ranging from
ischemia to hypoxia can generate influences that adversely affect
the musculoskeletal system.
As discussed previously, joint subluxation/dysfunction has
been submitted as a source of altered segmental sympathetic tone.
If joint dysfunction can induce a sympathetic response robust
enough to induce local or segmental vasoconstriction, spinal subluxation/dysfunction may be associated with decreased circulation to segmentally supplied tissues. Cutaneous signs are found in
altered texture, moisture, and temperature. Chiropractic adjustments would then have the potential to improve circulation by
restoring joint function and removing the source of sympathetic
irritation.
Musculoskeletal integrity and function are additional factors
directly affecting the circulatory system. The venous and lymph
systems are driven by skeletal muscle movements and changing
intrathoracic and intra-abdominal pressures. A healthy respiratory
pump depends on a functioning diaphragm and flexible spine and
rib cage. Conditions or injuries that lead to the loss of musculoskeletal mobility and strength result in a potential net loss of
functional capacity of the musculoskeletal system and its ability
to move blood and lymph. Muscle injury or disuse leads to an
accompanying loss of vascularization in the affected tissues, and
additional blood and lymph flow impedance may occur. Blood
vessels pass through muscle, and it is reasonable to assume that
marked contraction of the muscle will impede circulatory flow,
especially on the venous side, where pressures are low. Therapy
directed at improving mobility and skeletal muscle strength has
the potential to improve the functional capacity of the musculo�
skeletal system and improve circulation.407
It has not been established, however, whether manipulation
specifically acts through the nervous system to affect the blood
supply or by altering the adverse musculoskeletal influences that
are interfering with the controls and regulations of vasomotor
function. It is likely that both concepts are possible.
APPLICATION OF ADJUSTIVE THERAPY
Once a working diagnosis is established and a decision is
reached to use adjustive therapy, the chiropractor and patient
need to establish the therapeutic goals of treatment and decide
what specific adjustive methods to apply (Figure 4-24). The
decision is influenced by factors such as the presence or absence
Chapter 4â•… Principles of Adjustive Technique |
ADJUSTIVE THERAPY DECISION-MAKING
Manipulable
condition
Yes
Establish
therapeutic
goals
Yes
Rule out
contraindications
No
Apply nonadjustive
therapy or refer
No
Determine
which joints
to adjust
Determine
adjustive
vectors
Select and
apply adjustment
Figure 4-24â•… Factors to consider before selecting and applying an
adjustment.
of complicating disorders and the patient’s age, size, flexibility, physical condition, and personal preferences. The ability to
make a correct assessment and decision is affected by the doctor’s knowledge of anatomy, biomechanics, contraindications to
adjustments, and adjustive mechanics.
Before adjustments can be applied, the doctor must determine which joints or spinal regions to adjust and what adjustive movements and vectors to generate (see Figure 4-24). The
decision is a clinical one based on the presenting condition and
physical findings (Box 4-14). The final decision must be placed
within the context of the local anatomy and the geometric plane
of the articulations, the nature of the patient’s health status,
and any underlying disease processes. These factors and the
mechanical characteristics of the adjustment to be applied will
influence positioning of the patient, the specific contacts, the
Box 4-14
uestions and Factors in the
Q
Determination of Which Joints to Adjust
Is the condition affecting one or multiple levels?
Is the condition affecting one or both sides of the spine?
Will one or multiple adjustments be needed?
Site and side of subjective and palpable pain
Side of reactive soft tissue changes (e.g., altered
muscle tone)
Site and direction of restricted or painful motion
Site and directions of restricted end play or joint play
121
degree of appropriate preadjustive tension, the magnitude of
the applied force, and the direction of the adjustive thrust (Box
4-15). The ultimate goal is to select and apply a safe, comfortable, and effective adjustment that allows the doctor to localize and focus the adjustive forces to a specific region or motion
segment.
Joint Anatomy, Arthrokinematics, and
Adjustive Movements
Knowledge of spinal and extremity joint architecture, facet plane
orientations, and arthrokinematics is necessary for sound application of adjustments. Most adjustive techniques are directed at
producing joint distraction. Spinal adjustments are more likely to
induce effective movements when the clinician has a fundamental understanding of how joints are configured and what adjustive
vectors and forces are likely to efficiently generate joint movement
without producing joint injury.
The application of prone adjustive technique can be used to
illustrate this point. In the thoracic spine, the articular surfaces
are relatively flat. The superior articular processes underlie (are
anterior to) the inferior articular processes and on average form
an angle of approximately 60 degrees to the horizontal. During
segmental flexion in the thoracic spine, the posterior joint surfaces
glide apart along their joint surfaces. During extension, the posterior joint surfaces glide together. With maximal extension, there is
the potential for the articular surfaces to tip apart at their superior
margins (Figure 4-25).
When thoracic dysfunction is treated with prone thoracic
adjustments, it is common for the adjustive vectors to be delivered
in a direction that approximates either the disc plane or the facet
planes. The thrusts that parallel the disc plane are perpendicular
to the spine and will likely induce forward translation of the contacted segments (Figure 4-26). This thrust is also likely to induce
angular movements of extension at the contacted level as the superior and inferior segments move toward the shallow depression
that is created by the forward translation of the contacted area (see
Figure 4-26).408 There is also a possibility that gapping will occur
in the facet joints superior to the point of contact resulting from
forward translation of the contacted area and its superior facet.
In contrast, a thrust delivered P-A and inferior-to-superior
(I-S) along the facet planes is commonly applied to induce more
gliding distraction in the facet joint inferior to the point of contact (Figure 4-27). This approach is applied to induce the gliding
movements that occur during segmental flexion. Therefore, the
traditional approach is to direct the adjusting vector perpendicular
to the thoracic spine (P-A), when treating a joint with decreased
extension (flexion malposition) (see Figure 4-26) and more superior along the facet planes (P-A and I-S) when treating a joint with
decreased flexion (extension malposition) (see Figure 4-27).
However, recent findings on the biomechanical properties of
prone thoracic adjusting bring into question whether altering the
P-A direction of adjustive vectors on prone stationary patients
can effectively change the movement induced in the spine.35 For
example, can changing a prone adjusting vector from a perpendicular P-A orientation to a more P-A and I-S vector induce segmental flexion? Bereznick, Ross, and McGill35 make a compelling
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| Chiropractic Technique
Box 4-15
Factors Governing the Selection of and Specific Application of Adjustive Methods
Anatomic Location Of Joint Disorder or
Dysfunction
Morphology of tissues: size, strength and mobility of structures
Some areas necessitate more power (mass and leverage).
Patient’s Age and Physical Condition
Ability to assume specific positions; degree of pretension (force,
mass, leverage, and depth of thrust) the patient can withstand;
stress to adjacent spinal or extremity joints and soft tissues
Patient’s Size and Flexibility
Large or inflexible patient: need increased mechanical
advantage in the development of pretension and thrust
Table selection: height, articulating vs. nonarticulating,
release or drop pieces, mechanized
Method: leverage and type of thrust (e.g., push vs. pull)
Flexible patient
Focus force preloading of joint: removal of articular slack,
use of non-neutral patient positions
Selection of method: shorter lever methods
Presence of Mitigating Disorders or Defects
Pre existing congenital or developmental defects
Pre existing degenerative defects
Coexisting disease states
Adjacent motion segment instability (focus force minimize
stress to adjacent joints)
Specific Mechanical and Physical Attributes
of Adjustive Methods
Adjustive Localization and Pretension
Patient position
Doctor position
Contact points
Leverage
Adjustive Thrust
Leverage
Velocity
Amplitude (depth)
Mass
Point of delivery
Pause-nonpause
Short Lever Preferred to Long Lever
Issue of specificity
Patient of manageable size
Flexible patient
Patients with clinical motion segment instability
Long Lever Preferred to Short Lever
Spinal regions where additional leverage is desired
Patient size and flexibility demand additional leverage and
power
Doctor’s Technical Abilities and Preferences
Patient treatment preferences
Cannot compromise safety and effectiveness
A
B
C
Figure 4-25â•… A, The thoracic facets lie at a 60-degree angle to the
transverse plane. B, The facets separate and glide apart on flexion.
C, The facets approximate and glide together with extension. With maximal extension, the articular surfaces may gap at their superior margins
case that challenges this assumption by demonstrating that surface adjustive contacts cannot establish fixed contacts on underlying bone, fascia, or muscle. They demonstrated that the interface
between the superficial structures (skin and subcutaneous tissue)
and the underlying bone, muscle, and fascia is essentially frictionless.35 Therefore, any forces directed at the spine, other than perpendicular P-A forces, end up deforming and stretching overlying
structures without adding any directional forces (i.e., flexion) to
the spine. In this model, the more an adjustive force is directed
away from a perpendicular (P-A) orientation to the spine, the less
likely is a deformation and cavitation of the spine.
This emerging biomechanical research should lead the profession to question and further investigate some of its adjustive
mechanics assumptions and clinical applications. If changes in
prone thoracic vectors do not always induce the precise movements we anticipate, but are associated with a good clinical outcome, then perhaps it is not necessary to be precise with adjustive
vectors in all circumstances. Maybe a P-A thoracic thrust that
induces extension deformation of the spine and distraction in
the facet joints is effective at mobilizing the spine in a number of
directions. If this is the case, the profession can move beyond the
frustrations of trying to demonstrate clinically reliable and valid
Chapter 4â•… Principles of Adjustive Technique |
Prone: Segmental extension
Disc plane
vector
Figure 4-26â•… Effects of an adjustive force applied in a P-A direction
along the disc plane.
Prone: Segmental Flexion
123
methods for determining precise levels and directions of spinal
malpositions and restrictions. If the central clinically effective
component of adjustive therapy is the production of spinal movement it also frees the clinician to deliver a potentially more effective prone thoracic adjustment. For example, the more forces are
directed perpendicular (P-A) to the spine, the more likely they are
to induce spinal movement. The more the vectors are directed I-S
away from the spine, the more they are absorbed and dissipated
into the superficial soft tissues.
On the other hand, spinal adjustive therapy may be less effective than it could be because we have not developed the understanding and adjustive tools to the level necessary to be precise
and specific. Perhaps outcomes could be improved by furthering our understanding of adjusting biomechanics and the application of methods that could be counted on to produce specific
movements and effects. If simply changing our vector in a prone
neutral position is unlikely to induce any movement other than
extension or rotation, are there other options available that will
produce different effects? For example, can changing patient position produce different effects? If we maintain segmental flexion
or lateral flexion at the spinal level of desired effect, will a prone
adjustment be more effective at inducing the desired movement?
Can a supine adjustment, with the patient maintained in a flexed
position, produce more flexion? In the context of our present
understanding, it seems reasonable to apply modifications in PP
to try to effect different spinal movements and possibly improve
outcomes. Whether these approaches generate different spinal
movements and improved patient outcomes awaits further biomechanical and clinical research.
Adjustive Localization
Facet plane
vector
Adjustive localization refers to the preadjustive procedures designed
to localize adjustive forces and joint distraction. They involve
the application of physiologic and unphysiologic positions, the
reduction of articular “slack,” and the development of appropriate patient positions, contact points (CPs), and adjustive vectors.
These factors are fundamental to the development of appropriate
preadjustive articular tension and adjustive efficiency. Attention to
these components is intended to improve adjustive specificity and
to further minimize the distractive tension on adjacent joints. The
proper application of these principles should maximize the doctor’s
ability to focus his or her adjustive forces to a specific spinal region
and joint.
Longitudinal
distraction
Figure 4-27â•… Hypothetical effects of an adjustive thrust applied in a
P-A and I-S vector along the facet planes.
Physiologic And Unphysiologic Movement
Knowledge of the physiologic movements (normal coupled movements) of the spine and extremities is important in the process of determining how to localize and apply adjustive therapy.
Localization of adjustive forces depends on an understanding of
the normal ranges of joint movement and how combinations of
movement affect ease and range of joint movement. Each spinal
region and extremity joint has its own unique range and patterns
of movement. Knowing the ranges and patterns of movement
allows the doctor to know what combination of movements is
necessary to produce the greatest range of movement and what
combination is necessary to limit movement.
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| Chiropractic Technique
The spine can flex, extend, laterally flex, and rotate, but
in combination, these movements can act to either limit or
increase movement. Performance of movement in one plane
limits movement in another plane; flexion of the spine limits
the amount of lumbar rotation, and lumbar rotation limits the
amount of flexion. An additional coupling of motion in a third
plane can combine to further restrict or enhance the ROM. For
example, the greatest range of combined lumbar rotation and
lateral flexion is achieved if rotation and lateral flexion are executed in opposite directions and coupled with extension instead
of flexion.
Combined movements that allow for the greatest total combined range are referred to as physiologic movements, and combined movements that lead to limited movement are referred
to as unphysiologic movements. Right lateral flexion combined
with left rotation and extension is an example of physiologic
movement in the lumbar spine. Right lateral flexion combined
with right rotation or flexion is an example of unphysiologic
movement.
Unphysiologic movements bring the joints to positions of tension earlier in their ROM, limiting their overall ROM. Positioning
sections of the spine in unphysiologic postures during the application of adjustive therapy is a strategy referred to as joint locking.409
Application of this procedure helps focus the adjustive forces to
the affected region or joint and minimizes mobility at adjacent
joints. When adjacent spinal regions are placed in unphysiologic
positions, a block of resistance may be created superior or inferior
to the joint to be adjusted, establishing earlier preadjustive tension. Joints placed in their unphysiologic positions have greater
impact between joint surfaces, which may decrease the likelihood
of paraphysiologic joint movement and gapping at those joints.
The region and motion segment to be adjusted is placed in
the transition area between unphysiologic motion and physiologic motion or between sections placed in unphysiologic locking (Figure 4-28). The joints to be adjusted must have sufficient
slack remaining so that the adjustive thrust may induce gapping
or gliding within the joint’s physiologic range. If an adjustive
thrust is delivered against a joint placed in its close-packed position, there is a greater risk of inducing joint injury. Placing joints
in unphysiologic positions may be especially valuable in circum-
Transition point
Figure 4-28â•… The joints above the level to be adjusted (L3 and L4) are
placed in unphysiologic position (flexion, left rotation, and right lateral
flexion) to develop locking of the joints above the level to be adjusted.
stances in which clinical joint instability is suspect at adjacent
levels.
Reduction of Articular Slack
Articular slack refers to the joint play (JP) present in all synovial
joints and their periarticular soft tissues. Although it is a normal
component of joint function, available slack should be reduced
during or before delivery of an adjustive thrust to improve the
likelihood of inducing joint cavitation. Reducing articular slack
helps isolate tension to the specific periarticular soft tissues that
may be limiting JP and impeding joint motion. The removal
of articular slack and the development of preadjustive tension
also help focus the adjustive thrust to the desired spinal level
or extremity joint. The energy and force generated by adjustive thrusts may be dissipated into superficial soft tissue and
adjacent articular soft tissue if preadjustive tension is not first
established.410,411
The doctor may reduce articular slack by passively distracting
the involved spinal region or joint or by altering patient positions
to move the joints from their neutral position toward their elastic
barrier. Joint distraction induced by the doctor may be developed
by the gradual transfer of body weight through the adjustive contacts or by directing tractional forces through the adjustive contacts. The degree of preadjustive tension is gauged by the doctor’s
sense of joint tension and by the patient’s response to pressure.
Excessive traction or compression of joints during the application
of adjustive procedures can lead to jamming of joints, uncomfortable contacts, and patient splinting. It is common for chiropractic
students to overdo articular slack reduction and preadjustive tension when first learning adjustive techniques.
Lighter contacts and less preadjustive tension are necessary
when patient discomfort and splinting are encountered. Joints
with limited mobility need less movement to reduce articular slack and are often adjusted closer to their neutral positions.
Joints with greater flexibility usually necessitate patient positions
that move the joint from neutral positions toward the elastic
barrier.
Patient Positioning. Preadjustive joint tension and localization are significantly affected by patient placement and leverage.
Localization of adjustive forces may be enhanced by using patient
placement to position a joint at a point of distractive vulnerability.
Locking adjacent joints and positioning the joint to be adjusted
at the apex of curves established during PP enhance this process
(Figure 4-29). Joint localization and joint distraction may be further enhanced if forces are used to either help (assist) or oppose
(resist) the adjustive thrust. Assisted and resisted patient positions
refer to principles involved during the adjustive setup and development of preadjustive tension.
Assisted and Resisted Positioning. The notion of applying
assisted and opposing forces during the performance of manipulation was first described relative to thoracic manipulation by
the French orthopedist Robert Maigne.412 In the chiropractic profession, Sandoz24 was the first to describe similar terms. Sandoz
proposed using the terms assisted and resisted to describe patient
positions that either assist or resist side posture (SP) lumbar adjustive thrust.24 Both methods are used to improve the localization of
preadjustive �tension. Their application is based on the mechanical
Chapter 4â•… Principles of Adjustive Technique |
A
B
C
Figure 4-29â•… Proper patient positioning is necessary to develop appropriate preadjustive joint tension. A, Sagittal plane movement (flexion)
and separation of the posterior element of the joint. B, Coronal plane
movement (lateral flexion) and separation of the joint away from the table
(left facet joints and disc). C, Transverse plane movement and development of counter-rotational tension and gapping of the left facet joints.
principle that the region of maximal tension will be developed at
the point of opposing counter-rotation.413
Assisted and resisted patient positions are distinguished from
each other by the positioning of vertebral segments relative to
the adjustive thrust. In both circumstances, the trunk and vertebral segments superior to the adjustive contacts are prestressed in
the direction of desired joint movement. In the assisted method,
the contacts are established on the superior vertebral segments,
and movement of the trunk and the thrust are in the same direction (Figure 4-30, B). Resisted procedures use patient positions
in which the segments superior to the adjustive contact are prestressed in a direction opposing the adjustive thrust. In the resisted
method, the contacts are established on the lower vertebral segments, and the direction of adjustive thrust is applied opposite the
direction of trunk movement (see Figure 4-30, A).
Sandoz24 has suggested that resisted positions bring maximal
tension to the articulations superior to the established contact
(e.g., contact at the L3 mammillary inducing tension at the L2-3
motion segment and above) and assisted positions bring maximal
tension to the articulation inferior to the established contact (e.g.,
L2 spinous contact inducing tension at the L2-3 motion segment
and below). In the assisted method, the area of countertension is
inferior to the point of contact because the inferior segments are
125
stabilized or rotated in a direction opposite the adjustive thrust
(see Figure 4-30). In the resisted approach, the site of countertension is superior to the point of contact because the segments
above the point of contact are rotated in a direction opposite the
adjustive thrust (see Figure 4-30). Research by Cramer and coworkers265 has demonstrated that side posture-resisted lumbar
mammillary push adjustments induce positional and postadjustment gapping in the articulations superior to the level of contact.
In principle, either method can be used to induce the same joint
motion within the same articulations. With assisted patient positions, the thrust is oriented in the direction of joint restriction;
with resisted patient positions, the thrust is directed against the
direction of joint restriction.
Assisted and resisted patient positions have been most frequently discussed relative to the development of rotational tension
of the spine. In theory, the same methods and principles may be
applied to treat dysfunction in lateral flexion or flexion and extension. To treat a loss of right lateral bending in the lumbar spine
using the assisted method, the patient is placed on the right side
with a roll placed under the lumbar spine to induce right lateral
flexion. A contact is then established over the left mammillary of
the superior vertebra, with an adjustive vector directed anteriorly
and superiorly (Figure 4-31). To treat the same restriction with
a resisted method, the same patient postioning should be maintained, but the left mammillary process of the inferior vertebra
is contacted with a thrust delivered anteriorly and inferiorly (see
Figure 4-31). Although both techniques are directed at distracting
the left facet joints, one is assisting and the other is resisting the
direction of bending.
To treat a loss of lumbar flexion with a side posture-assisted
method, the patient should be placed on either side and segmental flexion induced, the superior vertebrae of the involved motion
segment should be contacted, and the thrust should be anterior
and superior. Conversely, without changing PP, the same restriction could be treated with a resisted method by simply contacting
the lower vertebrae and thrusting anteriorly and inferiorly (Figure
4-32). The same principles described for flexion can easily be
applied to treat an extension restriction, the only difference being the
prestressing of the patient into segmental extension.
When applying side posture adjustive thrusts in the treatment
of lateral flexion, flexion, or extension, it is typically less stressful
to the doctor’s wrist and shoulder to couple P-A thrusts with an
I-S vector, as opposed to a coupled superior-to-inferior vector. The
superior-to-inferior vector induces a posture of wrist extension and
internal shoulder rotation that is uncomfortable and possibly injurious. Therefore, lateral flexion and flexion adjustments may be more
safely and comfortably delivered with assisted patient positions and
extension adjustments delivered with resisted patient positions.
The principles presented for assisted and resisted lateral flexion
and flexion-extension side posture adjustments are potentially limited by the same biomechanical issues discussed previously relative
to prone thoracic adjustments. Biomechanical research indicates that
it is very unlikely adjustive contacts can establish effective tension
with underlying bone, fascia, or muscle.269 In this context it seems
unlikely that adjustive vectors directed superiorly or inferiorly
will generate forces helpful in assisting in the production of lateral
flexion or flexion-extension movements. It seems more �plausible
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| Chiropractic Technique
A
4-30A, B
B
Figure 4-30â•… A, Resisted patient positioning with mammillary contact established on the inferior vertebra. B, Assisted patient
positioning with spinous contact established on the superior vertebra. Both procedures are applied to produce left rotation.
Resisted
Assisted
Figure 4-31â•… Adjustment for loss of right lateral flexion. With a
Resisted Assisted
resisted method, the contact is established on the left mammillary process
of the inferior vertebra. The assisted method incorporates a contact established on the left mammillary process of the superior vertebra.
Figure 4-32â•… Adjustment for loss of flexion using resisted (inferior
that �attention to PP and factors that assist in deforming the spine
in lateral flexion or flexion-extension would be potentially most
effective.
Although the classification scheme of assisted and resisted
patient positions is useful for contrasting different methods, it
does create a possible void for those procedures in which both
hands establish adjustive contacts and both deliver opposing
adjustive thrusts. Counterthrust procedures, commonly applied
during rotational spinal adjustments, do not conform to the
strict definitions of assisted or resisted PP because these terms
are defined relative to the delivery of one thrust, not two. In
methods applying counterthrust techniques, both arms thrust;
one arm establishes an assisted position and thrust as the other
develops a resisted position and thrust. Based on the previous
guidelines, they do not fit either category. To distinguish them
from single-thrust patient positions, we suggest referring to them
as counterthrust procedures (Figure 4-33).
Neutral Positioning. Neutral patient positions refer to circumstances in which the patient and articulations are left in a relatively
neutral position during the delivery of an adjustive thrust. Any
preadjustive reduction of articular slack is established through
the doctor’s contacts without significant alterations in PP (Figure
4-34). Neutral positioning may be practical in some procedures
such as prone spinal adjustive positions but impractical in others
such as side posture rotational adjustments in which rotational
leverage works to the doctor’s advantage.
Principles of Patient Positioning. To take advantage of the
potential increased specificity and efficiency that modifications in
PP offer, the doctor must be aware of the various options available
and the principles that underlie them. Although one approach is
vertebra) or assisted (superior vertebra) methods.
Chapter 4â•… Principles of Adjustive Technique |
127
Segmental contact points
4-33
Figure 4-33â•… A counterthrust procedure applied to treat a lumbar right rotation restriction.
Adjustive Specificity
Figure 4-34â•… Prone thoracic bilateral thenar transverse adjustment
applied to induce segmental extension with neutral patient positioning.
not necessarily superior to the other, each method has unique attributes that may make it more appropriate in certain circumstances.
To make the appropriate distinction and effectively deliver adjustments, the doctor needs a clear understanding of each method’s
unique mechanical characteristics and differences. For example, a
thrust delivered against the left L3 mammillary of a patient lying
on the right side with shoulders in neutral may not have the same
mechanical effect as in the patient whose shoulders are rotated
toward the table into left rotation.
With the patient in the neutral position, the thrust against
the left L3 mammillary is typically and traditionally applied to
induce right rotation of L3 relative to L4 and the segments below
(Figure 4-35). If the same thrust is delivered with the patient’s
shoulders rotated into left rotation (resisted position), maximal
tension and cavitation may be induced in left rotation at the
ipsilateral articulations above (L2-3 and superior). If the doctor
wishes to induce right rotation at the L3-4 motion segment with
an adjustive technique that involves shoulder counter-rotation
and a mammillary contact, the patient should be placed on the
opposite side (left) with a mammillary contact established at L4
instead of L3 (Figure 4-36).
Adjustive specificity describes the degree to which an adjustment is
localized to a specific spinal region or joint. Historically the chiropractic profession has emphasized the value and application of
methods believed to focus maximal effect in one joint. Application
of the principles of PP and joint localization maximizes the
�potential for specific effects, but does not ensure that adjustive setups and thrusts will produce movement only at the desired level.
The spine is a closed kinetic chain, making it highly unlikely that
spinal movements can be induced at one joint at a time.264,269 Any
adjustive thrust will have some effect on the other components
of the three-joint complex and the joints superior to and inferior
to the contacted vertebrae.264
The adjustive objective is not to eliminate all adjacent movement but to stress the skills that increase the probability of producing regional and focused joint cavitation while minimizing
movement and tension at unwanted spinal regions and adjacent
joints.
Ross, Bereznick, and McGill269 conducted some groundbreaking work evaluating the level of applied adjustment and the level
of induced joint cavitation. They were able to localize the level of
thoracic and lumbar joint cavitations by fixing accelerometers to
the skin over the spinal column and measuring the relative time
it took for cavitation-induced vibrations to reach each accelerometer. Lumbar adjustments produced multiple levels of cavitation
in most cases (2 to 6). The average cavitation site was 5.29â•›cm off
the target level (at least one vertebra away) with a range of 0 to
14â•›cm. In the thoracic spine, the average cavitation site was 3.5â•›cm
off the target site, with a range of 0 to 0.95. Their research indicates that the tested procedures did not produce the frequency
of targeted joint-level joint cavitations desired. Lumbar SMT was
accurate approximately half the time. However, because lumbar
adjustments were associated with multiple cavitations, at least one
cavitation also typically emanated from the targeted joint. In the
thoracic spine, SMT appears to the more accurate. Other studies
evaluating cervical rotational adjustments and side posture lumbar
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| Chiropractic Technique
Figure 4-35â•… Assisted adjustment applied to
4-35
induce right rotation of the L3-4 joint using an L3
mammillary contact and neutral patient position.
Figure 4-36â•… Resisted method applied to induce
4-36
right rotation of the L3-4 joint. In this method, a
contact is established on the right mammillary of L4, with the patient
lying on the left side and the patient’s shoulders rotated posteriorly to
induce right rotation.
and SI adjustments also indicate less precision in producing cavitations to side or level to targeted joint.267,268
Research evaluating HVLA adjustive specificity depends on the
chiropractor’s initial judgment of which joint is being targeted. This
depends on the accuracy of the segmental contacts, the methods the
chiropractor applies, and the biomechanical assumptions he or she
has about the applied adjustment. The chiropractic profession has a
history of assuming that adjustive contacts can be focused to one vertebra. It is also common to assume that the joint below the level of
vertebral contact is the joint being targeted for treatment (adjusted).
There are some presumptions in this model that seem improbable. First, it is unlikely that surface adjustive contacts can be precise
enough to contact just one vertebra. In addition, surface contacts do
not appear capable of hooking or binding to underline vertebra and
individual vertebra.35 As mentioned previously, individual vertebra are
part of a closed kinetic chain, making it highly improbable that chiropractic adjustments can induce movement of a single vertebra.264,269
It is also unlikely that all adjustive methods are uniform in their
biomechanical effects and equal in their ability to focus adjustive
forces. It is possible that some methods are more likely to affect
joints above the level of contact or equally affect joints on either
side of the contact level. For example, side posture-resisted mammillary lumbar and SI adjustments have demonstrated cavitations
commonly occurring at levels above the contacted level.268,269 If
chiropractors were to apply selected side posture lumbar methods
with the intent of targeting joints above the level of adjustive contact, the specificity outcomes might be different. As our understanding of adjustive biomechanics deepens, our assumptions may
evolve and our concepts regarding adjustive specificity may change.
It seems likely that HVLA adjustments will be viewed more in
the context of being region-specific (several joints) rather that
single-level–specific.
The emerging biomechanical information concerning the
characteristics of HVLA adjustments raises the important clinical question of whether single-level localization of adjustive forces
or cavitation is materially associated with clinical outcomes. What
we say we do and what we really do may be two very different
things. Although this information should initiate reevaluation of
our clinical assumptions and possibly change our clinical approach,
it must also be emphasized that it is biomechanical research and
not clinical research. Clinical research is necessary to answer questions of clinical effectiveness. Basic science research cannot answer
the question of which adjustive procedures are the most effective.
They can guide the research, but answers to the questions of clinical effectiveness must be addressed with patient-centered clinical
research. The likelihood that adjustments have a regional rather
than a precise single-level effect does not diminish the demonstrated clinical effectiveness of chiropractic adjustive therapy. It
is possible that the principles we apply to achieve joint specificity
have a clinical effect and advantage not related to level of precise
joint cavitation. Furthermore, much of the research on adjusting
specificity is based on measuring the sites of joint cavitation, and it
is possible that the sites of cavitation do not always correlate to the
site of the focused adjustive force. It is possible that adjustive forces
are relatively focused and yet induce cavitation at multiple sites or
adjacent sites because the targeted joint is more fixed than adjacent
joints. Adjustive therapy rarely reaches maximal clinical effect with
several adjustments and, over time, the applied adjustments may
start to induce cavitation at the targeted joint as it becomes more
mobile and capable of cavitating. Clinical research comparing different adjustive approaches is necessary to determine if there are
clinical differences or advantages to one approach versus another.
Research evaluating the premise that “specific” HVLA adjustments produce better outcomes has not been conducted. This
research question cannot be clinically addressed until biomechanical evidence exists demonstrating that there are adjustments capable
of producing a specific targeted effect. Up to this point, the overwhelming majority of clinical outcomes research on chiropractic
adjustive treatment of mechanical spine pain has been conducted
using standard approaches and methods that assume specificity does
matter. The adjustments and vectors selected were applied with this
principle in mind. Although the elements associated with different adjustive methods and vectors may produce better results, it is
uncertain if this is a product of a localized specific effect. The outcome may have nothing to do with how a joint is moved or the precision of the level of effect. There are a number of possible clinical
effects, and some may be sensitive to the direction adjustive forces
generated and not germane to how the spine deforms and moves.
Adjustive Psychomotor Skills
There is a wide range of adjustive procedures within the chiropractic profession; some are unique to the profession, and some are
practiced by a wide variety of manual therapists. Each grouping
of adjustments has its own mechanical characteristics that depend
Chapter 4â•… Principles of Adjustive Technique |
on adjustive contacts, PP, doctor positioning (DP), and adjustive
vectors. Efficient and effective selections cannot be made without
an understanding of each adjustment’s unique physical attributes.
Several of the technique approaches are practiced as a package or
system (see Appendix 1). They are often the product of clinical
practice and usually include analytic procedures of assessment. It
is not uncommon for chiropractors to limit their practice to primarily one of these many systems or approaches.
We believe that the adherence to one methodologic approach
may be a disadvantage. A therapy or technique that works for
one patient or problem may not work on a different problem or
patient. An integrated approach that incorporates alternative technique approaches may provide effective options. Adjustive technique is a psychomotor skill that requires personal development
and modification. Limiting alternatives to one approach may
exclude techniques that fit the physical characteristics of the doctor or the patient.
Although some techniques differ dramatically, most thrust techniques share common basic mechanical characteristics and psychomotor skills. To effectively perform adjustive techniques, the
chiropractor must have a foundation in these common principles
and psychomotor skills. Each individual joint complex has specific
anatomic and biomechanical considerations that affect adjustive
therapy. As each spinal region and extremity joint is presented, the
unique relationship between regional anatomy, biomechanics, and
adjustive mechanics is discussed (see Chapters 5 and 6).
Patient Positioning
PP denotes the placement of the patient before and during the
delivery of an adjustment. It is an essential component of effective adjustive treatment. It is a learned skill, which is often overlooked during the instruction and learning of adjustive technique.
Proper attention to PP is critical to patient comfort and protection. Patients placed in awkward positions are apprehensive and
unlikely to relax. Improper selection can leave the doctor at a
mechanical disadvantage and in a position of increased risk of
injury. The doctor is also vulnerable to injury as he or she assists
patients in their positioning.
Whenever possible, the doctor should allow the patient to position himself or herself. The patient should be instructed on how to
comfortably assume or modify his or her position on an adjustive
bench. If it is necessary to assist a patient, the doctor should ensure
that his or her back is in a stable position and that the patient is
close to his or her center of gravity. Whenever possible, the doctor
should use the power available in his or her legs to assist with lifting,
pushing, or pulling movements.
As previously described, PP is critical to the development of
joint preadjustive tension, adjustive localization, and efficiency.
Adjustive localization and efficiency are products of adjustive
leverage, preadjustive tissue resistance, and joint locking. All
these factors in turn depend on PP. Increased tissue resistance
and locking of adjacent joints are developed by inducing opposing forces through non-neutral PP. By positioning the joint to be
distracted at the apex of secondarily established curves, joint distraction is increased, and the dysfunctional joint and spinal section is established as the area to receive the most distractive forces
(see Figure 4-29).
129
There is a variety of postures available, each offering its own
advantages and disadvantages. The selection of a specific position
is governed by the specific mechanical features of each patient position, the clinical condition being treated, and the specific preferences of the doctor and patient. The standard PP options include
prone, supine, standing, sitting, knee-chest, and side posture
position. Within each adjustive description presented in Chapters
5 and 6, the PP section describes and illustrates the mechanics
of PP, the type of adjusting table used, the position of the table’s
sectional pieces, and the appropriate use of any additional pillows or rolls. When indicated, the positioning of the extremities is
described to ensure proper segmental tension.
Equipment Varieties and Management
The development of the equipment used by chiropractors and other
practitioners of manipulation has taken place over time. Almost all
procedures make use of a table or bench of some sort. The first chiropractic table had a flat, wooden surface atop ornate turned legs.
It had no padding and no face opening, providing little comfort to
the patient. It was not until 1943 that the first pad was designed for
the adjusting table surface.414 As new tables were developed, attention was paid to PP and the location of the clinician, providing for
increased leverage and an advantageous adjacent stance.415
A wide range of specialized adjusting tables and equipment
is now available to enhance patient comfort and adjustive efficiency (Figure 4-37). Table options include flat benches, articulated tables, elevation tables, high-low (tilting) tables, knee-chest
tables, manual and automatic distraction tables, and drop-piece
tables. Some equipment is designed for the application of specific
techniques, but most tables may be used with any of the common
adjustive methods.
Regardless of the equipment used, some general habits should
be developed. A doctor should select a table height advantageous
to his or her physical attributes, use clean face paper on the headpiece of the adjusting table, and regularly apply a disinfectant to the
table. The appropriate table height varies depending on the patient’s
size, the doctor’s specific physical attributes, and the body area being
adjusted. The average table height for pelvic, lumbar, and thoracic
adjusting is the distance from the floor to the middle or superior
A
B
D
C
E
Figure 4-37â•… Specialized tables and equipment are used to enhance
patient comfort and adjusting efficiency. A, Headrest pillow. B, Pelvic
or Dutchman’s roll. C, Dorsal or pediatric block. D, Pelvic block.
E, Sternal roll.
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| Chiropractic Technique
A
A
B
Figure 4-38â•… A, Typical adjusting bench with brachial cut out.
B, Pelvic bench. (Courtesy Lloyd Table Company, Lisbon, Iowa.)
aspect of the doctor’s knee. For supine cervical adjusting, a higher
table may be selected to minimize stress on the doctor’s back.
Adjusting Bench. An adjusting bench (Figure 4-38) is a padded, nonarticulated, flat table with a face slot. It typically has a
brachial cut out to allow comfortable placement of the patient’s
shoulders in prone positions. A pelvic bench is very similar to the
standard adjusting bench. It is usually wider than the articulated
adjusting tables and lacks the brachial cut out commonly featured
on other adjusting benches (see Figure 4-38). The pelvic bench is
useful for side posture or supine adjustive methods, but is uncomfortable on patients’ shoulders in the prone position. The lack
of articulated sections limits the ability of adjusting benches to
modify patient positions and spinal postures. However, the use of
wedges or cylindrical cushions are effective ways to achieve similar
modifications in side posture or prone PP (Figure 4-39).
Articulated and Hydraulic Tables. An articulated table has
movable head, thoracic, pelvic, and foot pieces to properly accommodate the patient in both the prone, side posture, and supine
positions (Figure 4-40, A). High-low tables tilt from a vertical to
a horizontal position, making it easier for a patient to get on and
off the table (see Figure 4-40, B). Elevation tables have the ability
to adjust to variable heights for different procedures as well as for
different-sized doctors (see Figure 4-40, C).
When the patient is in the supine position on an articulating
table, the headrest should be closed and elevated, and all other
sections should be lowered to a level position. When performing
cervical or upper thoracic adjusting, the headpiece may be slightly
lowered. For prone positioning, to achieve a relaxed neutral posture, the footrest, pelvic, and thoracic sections should be elevated
slightly, and the headrest should be lowered slightly.
Knee-Chest Table. The knee-chest table (Figure 4-41) gets its
name from the position the patient assumes when on the table.
The patient’s chest and face are supported by a head and chest
piece and the patient’s knees rest on the padded base of the table.
The chest piece should be situated so that the patient’s spine
remains parallel to the floor.416 The lower thoracic and lumbar
B
Figure 4-39â•… Use of rolls and wedges to modify preadjustive patient
positioning. A, Use of a cylindrical roll to induce lateral flexion toward
the table (right lateral flexion). B, Use of a wedge to induce lateral flexion
away from the table (left lateral flexion).
spine are left in an unsupported and unrestricted position. It is
this feature that provides the table’s most unique and potentially
effective attribute. In this position the doctor has the mechanical
advantage to easily develop full adjustive pretension, especially
into extension. Consequently, this table may be most effective when applied in the treatment of lower thoracic and lumbar extension restrictions. It has also been suggested for those
patients with large abdomens for whom the prone position is
uncomfortable. Patients beyond the first trimester of pregnancy
may be more comfortable and have less anxiety in the knee-chest
position than prone when having P-A thrusts applied to the
lower back.
The attributes of the knee-chest table are also the features that
contribute to its greatest inherent risk for hyperextension injuries.
The risk of injury can be minimized by gently developing pretension and delivering shallow and nonrecoiling adjustive thrusts.
Although cervical, thoracic, and lumbar techniques can be performed in the knee-chest position, lower thoracic and lumbar dysfunctions are the areas more commonly adjusted in this position.
In a predicament, the knee-chest position can be approximated
by having the patient kneel on a pillow at the head end of the traditional table with the face on the headrest and forearms on the
armrests. The kneeling modification cannot duplicate the comfort
and modifications available in a knee-chest table and should be
used only in unusual circumstances.
Chapter 4â•… Principles of Adjustive Technique |
2
3
131
4
1
A
Figure 4-41â•… Knee-chest table.
4
1
3
2
B
Figure 4-42â•… Mechanical drop pieces on stationary articulated table:
(1) pelvic section cocking lever, (2) lumbar section cocking lever, (3) thoracic section cocking lever, (4) cervical section cocking lever. (Courtesy
Lloyd Table Company, Lisbon, Iowa.)
C
Figure 4-40â•… Articulated and hydraulic tables. A, Stationary: (1) foot-
rest, (2) pelvic section, (3) thoracic section, and (4) headrest. B, Highlow with vertical to horizontal tilt. C, Elevation table to variable heights.
(Courtesy Lloyd Table Company, Lisbon, Iowa.)
Some doctors and patients are quite apprehensive about kneechest positioning. In such circumstances, an articulated table may
be used to achieve a similar position. This may be accomplished
by slightly raising the pelvic piece and allowing the thoracic piece
to drop away.
Drop Tables. Mechanical drop pieces are available on any or all
of the sections of an articulated table (Figure 4-42). Drop mechanisms allow for the elevation of sectional pieces and the subsequent free fall of those sections when sufficient adjustive force
is applied against the patient. The drop sections elevate a fixed
amount (approximately 1⁄2 inch), but the degree of resistive Â�tension
varies. The amount of tension varies depending on the size of the
patient, the extent of established preadjustive tension, and the force
of the adjustive thrust. The degree of tension established in the
drop mechanism should not be ascertained by thrusting against the
patient. Tension should be determined by placing the patient on
the table and thrusting against the table, not the patient.
Although no supporting clinical data exist, drop-piece mechanisms have been promoted as a technology for increasing adjustive
efficiency. One position suggests that the degree of adjustive effort
and force may be reduced because the drop of the table decreases
the counter-resistance of the table and the patient. The other
assertion is that the force of the adjustive thrust is enhanced by
the counter-reactive force generated across the joint when adjustive thrusts are maintained through the impact of the drop piece.
Proponents of the first approach set low resistive tension on the
drop mechanism and apply multiple light shallow recoil thrusts.
The thrust is typically terminated before the drop mechanism has
completely terminated its drop. In the second approach, resistive tension of the drop mechanism is increased to the point at
which it can withstand the patient’s weight and additional loading applied from the doctor as he or she establishes pretension.
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| Chiropractic Technique
The thrust is nonrecoil and maintained until the drop mechanism has terminated its drop. One of the potential disadvantages
of the drop mechanism is the noise generated during the dropping
action, which makes it difficult to perceive specific joint movement with the thrust.
Distraction Tables. The distraction table (Figure 4-43) offers a
form of mechanical assistance for the application of manual therapy by having a fully movable pelvic section. The mobile pelvic
piece provides a long-lever action that allows the lumbar spine to
be positioned in or mobilized in flexion, extension, lateral flexion,
or rotation, as well as the combined movement of circumduction.
Technique procedures applied to mechanical distraction tables
commonly use a manual vertebral contact and either a manual or
motorized mobile pelvic section to create distraction. Distraction
tables can be used to evaluate spinal mobility, mobilize spinal articulations, or assist the doctor in the application of thrust techniques.
Most chiropractic table manufacturers (e.g., Leader, Lloyd, Zenith
Cox, Chattanooga and Hill) make a table that provides continuous
passive spinal distraction. This motion is produced as the motorized pelvic section of the table rhythmically depresses toward the
floor and back to a neutral position. Additional tension in rotation
and lateral flexion can be added by prepositioning the table into
the desired direction of rotation or lateral flexion. Some tables also
provide the added feature of linear axial distraction, focusing on
the long axis of the body (Figure 4-44).
When applying motion-assisted procedures for spinal joint dysfunction, the patient is typically positioned on the table so that
the pelvis is on the pelvic section. All recumbent positions (prone,
supine, and side posture) can be used. Because the use of linear
distraction is considered an enhancement to the clinician’s physical
application, virtually all recumbent techniques can be performed.
There are, of course, specific considerations for each joint to be
adjusted, such as the segmental contact point (SCP), vector of
thrust, and clinician position. Doctors should take caution not to
use excessive flexion with segmental distraction; excessive flexion
has the potential to overstretch the posterior joints and posterior
portion of the IVD.
Cervical Chair. The cervical chair (Figure 4-45) is a padded
chair with a movable backrest. The backrest is adjusted so that
Figure 4-43â•… Flexion distraction table. (Courtesy Lloyd Table Company,
Lisbon, Iowa.)
the patient’s spine remains straight and the area to be adjusted
lies just below the doctor’s forearm when the elbow is flexed to
90 degrees. The patient should sit with legs comfortably straightened and hands relaxed on the thighs. The cervical chair is used
exclusively for adjustments applied to the cervical spine and upper
thoracic spine.
A
L5
L4
L3
L2
B
Figure 4-44â•… A, Flexion-distraction of L3–L4 motion segment.
Patient is prone, with ankles strapped (optional). Clinician stands adjacent, in a lunge position (fencer stance), with the treating hand over the
L3 spinous process and other hand on the handle of the pelvic section.
Clinician depresses the pelvic section in a pumping action four to fire
times while maintaining cephalic pressure on the spine, than repeats the
four to fire pumps for one to two additional cycles, with a 30-second rest
between. B, Diagrammatic representation of contact over the L3 spinous
process, with the distractive vector shown.
Figure 4-45â•… Cervical chair.
Chapter 4â•… Principles of Adjustive Technique |
Doctor Positioning
Chiropractic is a physically demanding profession associated with
significant risk of occupational injury. Providing adjustive treatments subjects the doctor’s spine and upper extremities to numerous stressful postures and repetitive movements involving pushing,
pulling, twisting, bending, and lifting. A study was undertaken
to determine the prevalence and types of work-related injuries
among a random sample of chiropractors and to identify factors
associated with these injuries.417 Many chiropractors (40.1%)
reported experiencing injuries while working. Most of those injuries were classified as soft tissue injuries and occurred while either
performing (66.7%) or positioning (11.1%) a patient for manipulation. The clinician’s body parts most commonly injured were the
wrist, hand, and fingers (42.9%); shoulder (25.8%); and low back
(24.6%). These injuries were most often related to side posture
manipulation to the lumbar spine.417 To avoid fatigue and injury,
it is critical that DP involve sound body mechanics.
Good body mechanics start by selecting an appropriate table
height to maintain a balanced and relaxed stance. If the table is too
high, the doctor is at a mechanical disadvantage, unable to use the
strength and leverage of his or her lower torso and legs. Instead,
the doctor must rely on the strength of his or her upper body.
Excessive dependence on the upper body can lead to underpowered adjustments and repetitive stress injuries to the upper extremities. If the table is too low, unnecessary stress may be applied to
the doctor’s back as he or she attempts to accommodate the height
of the table. Accommodations to lower tables should be made by
bending at the knees and hips and abducting the thighs, not by
slouching with the trunk (Figure 4-46).
Whenever possible, the doctor should establish postures that
maintain symmetric and neutral joint positioning. Delivering
133
thrusts through articulations positioned at end range or in closepacked positions places additional tension on the joint capsule
and surrounding soft tissues. To perform safe and effective adjustments, the doctor needs to establish a stable kinetic chain through
the spine and extremities. Core spinal stability and muscular bracing of the involved extremity joints are essential to the application of manual therapy and adjustments in particular. Common
hazardous postures include excessive flexion and twisting of the
trunk, excessive internal rotation and abduction of the shoulder,
and unsupported extension of wrists.
Proper attention to DP applies equally to the cervical spine.
Unfortunately, this region is frequently overlooked during discussion and presentations of adjustive technique. The doctor should
maintain a stable neck position and avoid excessive cervical flexion to observe segmental contacts. Flexion of the neck encourages
slouching of the upper back and excessive stress on the posterior
soft tissues, and it weakens the stability of the neck and upper
back (Figures 4-46 and 4-47).
Another critical element in the efficient and effective use of
DP is the orientation of the doctor’s center of gravity relative to
the level of his or her adjustive contacts. The doctor’s center of
gravity should be placed as close as possible to the SCP and positioned so that his or her body weight can effectively be used to
establish preadjustive joint tension (see Figure 4-47). The effective use of body weight (mass) can minimize the effort expended
in developing preadjustive tension and in delivering an adjustive thrust. If the mass of the adjustive thrust is increased, force
can be increased during the adjustment without increasing the
velocity.410,411,418,419 Placing his or her center of gravity behind
the line of drive (LOD) allows the doctor to transfer appropriate body weight into the adjustive set-up and thrust. Using body
weight and leg strength saves energy for the adjustive thrust and
minimizes the workload on the upper extremities. This helps
minimize muscular effort and fatigue. As much as possible, the
doctor’s legs should bear the workload, thereby protecting his or
her own back.
There are a number of named doctor stances used to describe
the doctor’s position during the delivery of adjustments. They
commonly denote the position of the doctor’s lower extremities and trunk in relation to the adjusting table and patient.
Figure 4-48 illustrates two of the common stances; other modifications are discussed and illustrated in the regional sections on
adjusting.
Contact Point
A
B
Figure 4-46â•… A, Illustration of sound body
4-46A,
B
mechanics and doctor accommodating the table by
bending hips and widening his stance and maintaining neutral spinal posture. B, Example of poor body mechanics illustrating the doctor excessively flexing his spine and slouching over the patient.
The CP designates which hand is the thrusting hand and the specific area of the hand that develops the focus of the adjusting contact. Attention to localizing a portion of the hand as the CP helps
focus the adjustive force.258,260 However, it is also possible for adjustive contacts to be established too firmly on or near a bony prominence (e.g., pisiform). Excessively bony or penetrating contacts
can prevent an adjustment from succeeding by generating unnecessary splinting and resistance from the patient. Uncomfortable
contacts in the thoracic and lumbar spine may be associated with
postures involving excessive extension of the wrist or arching of
the hand. Uncomfortable contacts in the neck are often encountered when the lateral and bony edge of the index finger, rather
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| Chiropractic Technique
A
B
Figure 4-47â•… A, Illustration of poor side-posture doctor positioning. The doctor has dropped his head and upper back into
4-47A,
B
excessive flexion and has positioned his torso and center of gravity to superior and anterior to his contact point. This results in ineffective use of body weight and a stressful position on the doctor’s shoulder. B, Illustration of sound side-posture doctor positioning. The doctor’s center
of gravity and body weight are effectively positioned to reinforce the thrusting vector and establish a neutral and stable position for his shoulder.
Indifferent Hand
The indifferent hand (IH) specifies which hand is used to stabilize
the patient, fixate adjacent joints, or reinforce the contact hand.
The points of patient contact and forces necessary to maintain
positioning and stabilization are also presented within this category. The IH is not always passive during the delivery of an adjustment. There are circumstances in which the IH moves from the
realm of stabilization into either an assisting or counter-resisting
thrust. In such circumstances, both extremities deliver an adjustive thrust. In the illustrations throughout the text, when thrusting forces are delineated from stabilization forces, an arrow is used
to demonstrate adjustive vectors, and a triangle is used to demonstrate stabilization points (Figure 4-50).
A
B
Figure 4-48â•… Two common doctor positions. A, Square stance: feet
are parallel and aligned in the coronal plan. When accommodating a
lower table, the doctor attempts to maintain a neutral spinal posture
by widening the stance and bending at the knees and hips. B, Fencer’s
stance (lunge position): legs are separated at shoulder width or greater
and angled to the torso. The knees are bent, and the doctor’s back heel is
off the floor. This position allows the doctor to efficiently transfer weight
forward and inferior toward his front foot.
than the more padded palmar lateral surface of the finger, is used
as the contact. The CP may be described anatomically or by a
numbering convention developed to represent the common CPs
(Figure 4-49). This text describes the contacts anatomically.
Segmental Contact Point
The SCP specifies anatomically where the adjustive contact or
contacts are to be established on the patient. The SCPs are listed
and described specifically in this chapter and in Chapters 5 and
6. When possible, they are illustrated in photographs or drawings. The SCPs are typically referenced as bony landmarks. This is
intended to be illustrative and clarify the underlying focal point of
the adjustive force (Figure 4-51).
Segmental contacts focused at specific bony landmarks cannot
be established without contacting overlying or adjacent soft tissues. Adjustive contacts established at or near the level of the dysfunctional joint are referred to as short-lever (direct) adjustments.
Adjustive contacts established at some distance from the level
of the dysfunctional joint are referred to as long-lever (indirect)
Chapter 4â•… Principles of Adjustive Technique |
135
4
4
4
5
4
6
9
7
8
12
10
Segmental contact points
3
2
Figure 4-51â•… Segmental contact points are bony landmarks located
close to the joint(s) to be adjusted. In this illustration, segmental contacts
are illustrated for a spinous push-pull adjustment. Bony landmarks are
illustrative and clarify the focal area of contact. They are not meant to
imply that contact points are limted to bony structures. Overlying and
adjacent soft tissue strucures are obviously also contacted
1
11
Figure 4-49â•… Contact points on the hand: (1) pisiform; (2) hypothenar; (3) metacarpal or knife-edge; (4) digital, used typically with the
index and middle fingers; (5) distal interphalangeal; (6) proximal interphalangeal; (7) metacarpophalangeal or index; (8) web; (9) thumb; (10)
thenar; (11) calcaneal; and (12) palmar.
Figure 4-50â•… Arrows indicate adjustive vectors; triangle indicates
stabilization.
adjustments, and adjustments that combine short- and long-lever
contacts are referred to as semidirect adjustments.
In spinal adjusting, a single thrusting contact is conventionally
taken on the superior vertebrae of the dysfunctional motion segment. Methods that incorporate thrusting contacts on the lower
vertebra or both vertebrae of the involved motion segment are also
effective and in common use. Contacts established on the lower
vertebra of the dysfunctional motion segment establish a resisted
method; contacts on the superior vertebra establish an assisted
method; and contacts established on adjacent vertebrae establish
a counter-resisted method (see Figure 4-51). Assisted and resisted
methods are summarized in Table 4-3.
Hand contacts established near the level of desired adjustment are assumed to improve the specificity of the adjustment,
and research indicates chiropractors are capable of developing an
area of focused force within the broader area of their contact.260,261
Whether specific short-lever contacts are universally associated with more specific successful joint cavitations is in doubt.
It appears that short-lever prone thoracic adjustments do induce
relatively specific effects as compared with side posture lumbar
adjustments.269 However, research indicates that employing a
short-lever contact and thrust in side posture lumbar adjustments
works against the doctor’s ability to induce joint cavitation.420 The
authors conclude that “successful generation of cavitation during
side posture lumbar manipulation requires emphasizing forces to
areas on a patient remote from the spine such as the pelvis and/or
lateral thigh.”420 Although focused short-lever contacts may produce a more local force in the spine, it is apparent that additional
added points of leverage are necessary to induce sufficient lumbar
axial rotation and cavitation.
If a local focused force is desired, then errors in the placement
of adjustive contacts may lead to the localization of adjustive forces
at undesired segmental levels. However, this does not imply that
it is always desirable or possible to establish a segmental contact
over a single vertebra. What is important is the ability to locate
contacts in a manner that focuses the adjustive forces and desired
movements in the joints or region to be adjusted.
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| Chiropractic Technique
Table 4-3
Comparison of Assisted, Resisted, and Counter-Resisted Spinal Adjustive Methods*
Segmental contact
point
Adjustive vector
Assisted
Resisted
Counter-Resisted
Superior vertebra
Inferior vertebra
Adjacent vertebra
Direction of joint restriction
Opposite direction of joint
restriction
Superior contact: direction of
restriction
Inferior contact: opposite
direction of restriction
*To be biomechanically efficient with adjustive methods, the patient positioning used should prestress the patient dysfunction joint(s) in the direction of the restriction of movement and the
indicated level of contact taken. The patient can remain in the neutral position and still have these principles apply.
A number of the adjusting methods used by chiropractors
involve close physical contact between the patient and the doctor.
The nature of this contact, if not properly explained, can lead to
misunderstandings and complaints of inappropriate touching. It
is paramount that doctors explain the procedures they are going to
use and receive permission to proceed before applying treatment.
Explanation of procedures is essential, followed by the questions
“Do you understand?” and “Is it okay?” These give the patient an
opportunity to question or refuse treatment.
The chiropractic educational process demands the development
of highly perfected manual palpation and therapy skills. Students
learn these skills by voluntarily practicing on each other. In the process there tends to be a desensitization to touch, disrobing, examination, and treatment procedures through familiarity. However,
naïve patients will not feel that familiarity. Therefore, it is important to be attentive to procedures that chiropractors may take for
granted but that patients may look on in an entirely different manner. Casual and unconscious contact with sensitive body parts may
go unnoticed by the practitioner but not by the patient. Doctors
must be mindful and aware of the potential to inadvertently touch
sensitive areas during the application of adjustive procedures.
Methods to be especially conscious of include supine thoracic adjustments and side posture lumbar or pelvic adjustments.
During supine adjustments, unwanted contact between the doctor and the breasts of the female patient or between the breasts
A
of the female doctor and the patient can become an issue. This
can be minimized by placing a small pillow or roll between the
patient’s breasts and arms or between the doctor and the patient’s
arms (Figure 4-52). In side posture adjustments, inadvertent
contact between the doctor’s genitals and the patient’s thigh can
occur. This can easily be avoided if the doctor is simply aware of
this potential and positions himself or herself accordingly.
Any examination or treatment procedure performed on a member of the opposite sex that involves exposure or contact with the
genitals or rectal region should be performed only when an assistant
is in the room. The internal mobilization or manipulation of the
coccyx is an example of a procedure for which this is warranted.
Tissue Pull
Superficial tissue traction (pull) is typically applied during the
establishment of an adjustive contact. Proper tissue pulls are necessary to ensure that a firm contact is established before a thrust is
delivered. If this is not taken into consideration, the CP may slip
during the thrust and dissipate the adjustive force into superficial
soft tissues and decrease the doctor’s ability to impart a force to
the spine. The IH may be used to draw the tissue slack as the CP
is established. Tissue pulls are commonly initiated in the direction of the adjustive thrust and, as such, will not be listed separately. Prone patient P-A thrusts are a common exception. In this
circumstance the direction of tissue pull is often irrelevant. Tissue
B
Figure 4-52â•… A, Supine thoracic adjustment in the midthoracic spine illustrating the use of a small roll to pad the patient’s anterior chest.
B,€Use of a rectangular pillow to minimize contact between the doctor’s anterior chest and patient.
Chapter 4â•… Principles of Adjustive Technique |
pulls up or down the spine are appropriate and are applied to
prevent the doctor’s contacts from sliding. The direction of tissue pull is based on the region of the spine and the doctor’s
preference.
Vector (Line of Drive)
The vector, or LOD, indicates the direction of the adjustive force
(thrust). Historically, the profession has described the direction
of adjustive thrusts in anatomic terms. For example, an adjustive
vector delivered with a patient in the prone position with a ventral
and cephalic orientation is described as a P-A vector and an I-S
vector. This text adheres to this standard and illustrates the direction of adjustive vectors in drawings and pictures with the aid of
solid arrows (see Figure 4-50).
Attention to alignment is necessary to ensure anatomically
sound, specific, and efficient adjustments. To produce joint distraction and movement without producing injury, the doctor
must have knowledge of the functional anatomy and kinematics
and match the adjustive vector accordingly. Misguided Vs may
lead to unwanted joint compression, joint tension, ineffective dissipation of forces, or joint cavitation at undesired levels. A single
adjustive thrust and cavitation may not free multiple directions
of joint restriction.421 Therefore, at times, a single articulation
may be adjusted in multiple directions, with different adjustive Vs
applied for each adjustive thrust.
Thrust
The adjustive thrust can be defined as the application of a controlled directional force, the delivery of which effects an adjustment. The adjustive vector describes the direction of applied force;
the adjustive thrust refers to the production and implementation
of that force.
The adjustive force is typically generated through a combination of the practitioner’s muscular effort and body weight transfer.
The chiropractic adjustive thrust is a ballistic HVLA force designed
to induce joint distraction and cavitation without exceeding the
limits of anatomic joint motion.
The thrust is the adjustive component, which, if delivered
incorrectly, carries the greatest risk of patient injury. Adjustive
thrusts performed with too much force, depth, or pretension
carry the risk of exceeding the limits of physiologic joint movement. It takes extensive training and time to perfect adjustive
skills and the ability to sense and control the appropriate depth
and force of an adjustive thrust. This skill cannot be effectively
learned over the course of a few months or by attending weekend courses. Chiropractors have devoted years of training to refine
their manipulative skills, and in the hands of skilled practitioners,
manipulation carries a very low rate of complication.
There is a critical adjustive force that must be supplied by the
doctor to bring a synovial joint to cavitation and influence its
structural and functional relationships. The development of this
force depends on a multitude of factors, including stiffness and
elasticity of the joint and patient, the proportion of impacting
energy entering the joint and patient, and the amount of joint
distraction at which cavitation takes place. These parameters are
governed by numerous properties of the patient, the doctor, the
joint, and the adjustive process.335
137
The average adjustive force produced by spinal manipulation
can be expressed in terms of the impact kinetic energy (mass and
velocity) of the clinician and the combined mechanical resistance
to deformation (stiffness and elasticity) of both clinician and
patient.343 This necessitates acquiring reflex contractile speed and
stabilizing contractions of specific muscles (frequently the triceps
and pectorals), as well as having enough applied leverage and body
mass. It is thought that mechanical assistance can be used to augment these physical attributes.
The advantage of leverage and use of the doctor’s body mass
to induce lumbar joint cavitation is illustrated by recent research
that demonstrates that dropping the doctor’s body weight through
CPs established on the patient’s posterior pelvis or lateral thigh is
necessary to induce lumbar cavitation.420 The authors concluded
that “successful generation of cavitation during side posture lumbar manipulation requires emphasizing forces to areas on a patient
remote from the spine such as the pelvis and/or lateral thigh.”420
The use of preadjustive tension can limit the dissipation of
thrust energy that occurs because of damping forces. Preloading
the joint limits further motion during the thrust so that force and
energy are not lost to other areas.410 Use of preliminary distraction means that the thrust has to supply only the remainder of
the force necessary for joint cavitation, diminishing the physical
requirements of the clinician. Therefore, the resulting enhanced
efficiency facilitates a more gentle adjustment419 with less exertion
by the clinician.
If preadjustive tension or countertension can be produced
through a mechanical device (adjusting table), theoretically even
less force, speed, and energy will be required from the clinician.
There are manual and motorized mechanical assistance components to adjusting tables. One such modification is the dropsection mechanism, representing a form of manual mechanical
assistance. Another modification is a moving table section, representing a form of motorized mechanical assistance.
Adjustive thrusts may be delivered in a variety of ways. Some
of the common distinguishing attributes include the physical
means the doctor uses to deliver the thrust (e.g., arm-centered
thrust vs. body-centered thrust) (Figure 4-53), the positioning of
the joint when the thrust is delivered (e.g., in a neutral position
compared with a point near the joint’s end ROM), and whether
the adjustment is delivered with or without an active recoil422 or
whether the thrust is delivered with a postpretension pause or
nonpause.
Adjustive thrusts are not always manually delivered. A number of mechanical thrust devices have been developed. Some are
designed for hand-held application (Figure 4-54), and others are
simply positioned by the doctor and do not require the doctor to
hold the instrument during the application of the thrust. Whether
these devices produce the same physical and therapeutic effects as
manual thrust techniques remains untested.
Recoil Thrust. The recoil thrust involves the application of an
HVLA ballistic force, characterized by the delivery of an active
thrust coupled with a passive recoil. The recoil thrust is produced
by inducing rapid elbow extension and shoulder adduction,
�followed by passive elbow flexion. The active thrust is induced
by simultaneously contracting the pectoral muscles and extensor
muscles of the elbows. The recoil is induced by rapid cessation of
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| Chiropractic Technique
A
Figure 4-54â•… Prone manually assisted instrument (activator) adjustment illustrating sacroiliac (SI) joint application.
B
C
Figure 4-53â•… A, Illustration of recoil thrust. The
4-53A, B, C
body is held in stationary position, and thrust is generated by rapid acceleration at the elbows. The thrust is very shallow, with
a quick termination, followed by an elastic recoil as full elbow extension
is reached. B, Illustration of shoulder-drop thrust. The body is held in a
stationary position, and the thrust is generated through a quick depression (elongation) at the doctor’s shoulder. The doctor maintains a light
contact after terminating the thrust to dampen reverberations generated
by the shoulder thrust. C, Illustration of body-drop thrust. The thrust is
generated by acceleration of the doctor’s body weight through the adjustive contact. Transfer of body weight is generated by transferring weight
from the doctor’s heels toward the front of his feet. This is usually accomplished by inducing slight ankle dorsiflexion, knee flexion, and flexion
of the trunk. Body-drop thrusts are often combined with shoulder-drop
thrusts to produce a more rapid and rigid thrust and kinetic chain.
the thrust and the elastic rebound that results from impact with
the patient and the stretch of the doctor’s arms.18
This method typically involves establishing a segmental �contact
with one hand while the other hand reinforces the �contact hand.
Both arms thrust equally during the delivery of the adjustment;
the vector is determined by the orientation of the doctor’s episternal notch relative to the CP. This thrust is most commonly
delivered with the patient in a relaxed position, with neutral joint
positioning and little or no joint prestressing (see Figure 4-53).
Impulse Thrust (Dynamic Thrust). Impulse thrusts also use
an HVLA force but are performed in a manner to minimize the
normal elastic recoil that occurs after the quick cessation of an
adjustive thrust. This is accomplished by maintaining mild pressure and contact with the surface for a short time after the termination of the adjustive thrust. The adjustive velocity may be
varied, with either a slow or fast termination.
Impulse thrusts are most commonly delivered with the
affected joint prestressed to reduce articular slack, but they
should not be delivered with the joint stressed beyond its elastic
limits. Impulse thrusts may be primarily arm centered or body
centered, or their forces may be combined through the doctor’s
arms and body.
All adjustive thrusts involve relatively high-velocity forces, but
vary in the degree of associated body weight coupled with the
adjustment. When less mass and total force are desired, the thrust
is typically delivered only through the upper extremities. This is
commonly the case in the adjustive treatment of the cervical spine
and small extremity joints and in the treatment of pediatric, geriatric, or frail patients.
During the delivery of arm-centered thrusts, the doctor’s torso
is stationary. The adjustive force is produced by the initiation of
pushing, pulling, or rotation forces generated through the doctor’s
Chapter 4â•… Principles of Adjustive Technique |
A
139
B
Figure 4-55â•… A, Prone unilateral hypothenar transverse push adjustment delivered to induce right rotation. B, Prone crossed bilateral hypothenar
transverse counterthrust adjustment delivered to induce right rotation.
forearms, elbows, and shoulders (see Figure 4-53). Arm-centered
thrusts may be delivered through one arm or both arms. When
one arm is the focus of the adjustive force, the other arm (the IH)
either reinforces the contact or stabilizes the patient at another
site. When used for stabilization, the IH maintains the patient in
a neutral position or induces positions or forces that assist or resist
the adjustive force (Figure 4-55).
When more total force is desired, the doctor transfers additional weight from the trunk or pelvis into the adjustive thrust. In
body-centered (body-drop) thrusts, the majority of the adjustive
force is generated by propelling the weight of the doctor’s trunk
through the adjustive contacts (see Figure 4-53). This is accomplished with a quick and shallow flexion of the doctor’s trunk
and lower extremities, along with a simultaneous contraction of
the abdominal muscles and diaphragm. Schafer and Faye421 have
described the abdominal and diaphragmatic contractions as a
process similar to the event that occurs during sneezing.
During the delivery of body-drop thrust, it is critical that
the upper extremities remain rigid. If the joints of the upper
extremity give way during the delivery of an adjustive thrust,
the adjustive force is dissipated. Rigidity is ensured by locking
the upper extremity joints and by combining the trunk acceleration with a simultaneous shallow thrust through the upper
extremities.
Adjustments delivered with prone patient position may be
�delivered as pure body-drop procedures, pure arm-centered thrusts,
or combined body drop–arm thrusts. Lumbar and pelvic side posture adjustments, which commonly demand more total force,
invariably involve the transfer of trunk and pelvic weight along with
a simultaneous arm thrust. To transfer the additional body mass
to the patient, the doctor typically establishes additional contacts
along the lateral hip or pelvis of the patient (Figure 4-56, A).
A common technique variation in side posture lumbar adjusting couples a segmental contact with a reinforcing thrust through
the doctor’s leg. Instead of the doctor’s weight resting against the
patient’s upper thigh and hip, a contact on the patient’s knee is
established. The impulse is then delivered by combining a pulling
impulse through the arm with a quick extension of the doctor’s
knee (see Figure 4-56, B). In this method, the leg provides the
additional leverage and force instead of the doctor’s body weight.
Nonpause Thrust. After the removal of articular slack, a thrust
may be delivered with or without a pause. When the thrust is performed without a pause, the slack is removed, and the thrust is
delivered by accelerating and thrusting at the point of appropriate
tension. An illustrated example is a wave crashing on the beach;
removal of slack relates to the wave rolling toward the beach, and
the thrust corresponds to the wave breaking against the shoreline.
This approach is effective in maintaining adjustive momentum
and avoiding patient guarding.
Pause Thrust. When thrusts are performed with a pause, the
doctor takes a moment to assess the degree of established joint
tension and tissue resistance before thrusting. This allows testing
of the set-up and evaluation of the patient’s responses to tension
and pressure. If sufficient articular slack has not been removed or
if abnormal binding induces patient discomfort, the doctor may
modify the degree of preadjustive tension or the adjustive vector
before applying the thrust.
After the pause, the doctor typically raises his or her trunk off
of the patient slightly to regain momentum and accelerate his or
her body weight into the thrust. During this process it is critical to
maintain the majority of established preadjustive tension through
the hands and points of secondary contact. The slight reduction
in joint tension may aid the doctor in ensuring that the thrust
is directed at the area of restriction and not too deeply into the
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| Chiropractic Technique
A
B
Figure 4-56â•… A, Side-posture resisted mammillary push adjustment with a thigh-to-thigh contact delivered to induce left rotation. B, Side-posture
resisted spinous pull adjustment with a shin-to-knee contact delivered to induce right rotation.
joint’s anatomic limits. However, if the doctor loses too much pretension, the adjustive force can dissipate and become nonfocused
and uncomfortable.
Assisted, Resisted, and Counter-Resisted (Thrust) Methods.
Assisted methods incorporate contacts established on and above the
superior vertebrae of the dysfunctional motion segment. They are
applied to focus the adjustive force in the joints inferior to the level
of segmental contacts. Assisted patient positions are incorporated if
modifications in neutral PP are used. The adjustive Vs are directed
to produce movement of the superior vertebra relative to the inferior vertebrae in the direction of joint restriction (direction opposite
malposition).
The adjustive thrust may be focused through a single segmental
contact or incorporate additional contacts and reinforcing thrusts
applied at levels superior to the segmental contact. Figure 4-57
illustrates the application of a short-lever method incorporating
a single level of focused thrust. Figure 4-58 illustrates a method
incorporating a segmental contact coupled with a superior hand
contact established on the patient’s ipsilateral forearm. In this
example additional leverage is provided through the superior contact, and both arms thrust to induce movement in the direction
of joint restriction.
Resisted methods incorporate segmental contacts established
on and below the inferior vertebrae of the dysfunctional motion
segment. They are applied to focus the adjustive effect in the joints
superior to the level of segmental contacts. Resisted patient positions are incorporated if modifications in neutral PP are used. The
adjustive Vs are directed to produce movement of the joint in
the direction of restriction (direction opposite malposition). This
is accomplished by moving motion segments inferior to the dysfunctional joint in the direction opposite the joint restriction.
Research by Cramer and colleagues266 has demonstrated that side
A
T7
T6
T5
Left
Right
B
Figure 4-57â•… Prone unilateral hypothenar
4-57
�
transverse push applied to treat a right rotation
restriction at T5-6. Segmental contact is established over the left T5
transverse process.
Chapter 4â•… Principles of Adjustive Technique |
A
T4
T5
T6
T5
141
T6
Right
T7
T8
B
Figure 4-58â•… An example of an assisted sitting
4-58
thoracic adjustment applied in the treatment of a left
rotation restriction at T5-6. This technique incorporates a segmental contact on the transverse process of the superior vertebrae of the dysfunction
motion segment with an assisting hand and thrusting contact established
on the patient’s ipsilateral forearm.
�
posture-resisted
lumbar mammillary push adjustments induce
positional and postadjusting gapping in the articulations superior
to the level of contact.
The adjustive thrust may be focused through a single segmental contact, but commonly incorporates additional contacts and
reinforcing thrusts applied at levels inferior to the segmental contact. Figure 4-59 illustrates the application of a short-lever method
incorporating a single level of focused thrust (very uncommon).
Figure 4-60 illustrates a method incorporating a segmental contact coupled with a distal contact established inferior to the level of
segmental contact. The vertebral segments superior to the contact
are rotated in the direction of restriction, opposite the direction of
the thrust, and preadjustive tension is localized to the articulations
superior to the contact. Additional leverage is provided through
the inferior contact established on the patient’s leg. At tension, a
thrust is delivered through both contacts to induce cavitation and
movement in the direction of restriction.
Counter-resisted methods incorporate segmental contacts
established on both sides of the joint or region to be adjusted.
Left
Figure 4-59â•… Prone thoracic resisted unilateral
4-59
hypothenar transverse push adjustment applied to
induce right rotation at the T4-5 joint. Adjustment is applied in the treatment of a right rotation restriction or a left rotation malposition at T4-5.
Segmental contact is established over the right T5 transverse process.
Pretension and the adjustive thrusts are directed in opposing
directions to maximize distraction across a given area and joint.
The adjustive thrust may be focused through segmental contacts
or may incorporate additional contacts and reinforcing thrusts
applied at levels superior to and inferior to the segmental contacts. In the spine this procedure is most commonly applied in
the treatment of rotational dysfunction. Figure 4-61 illustrates
the application of a short-lever method incorporating a neutral
patient position. Figure 4-62 illustrates a method incorporating
a segmental contact established on adjacent spinous processes,
coupled with additional points of leverage. The adjustive thrust
is applied in opposing directions through the segmental contacts and contacts established on the patient’s forearm and lateral
pelvis.
Although for didactic purposes it is useful to separate the
adjustive thrust into its component parts, it can be misleading
and distracting to the student who is trying to perfect the art of
adjusting. Instead of focusing on the act as a singular event, the
novice often tries to develop a thrust by mentally producing each
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| Chiropractic Technique
Right
Right
Left
Figure 4-60╅ An example of a resisted side-�posture
4-60
adjustment applied in the treatment of a right rotation restriction at L4-5. This technique incorporates a segmental contact
on the spinous process of the inferior vertebrae of the dysfunction motion
segment with a resisted leg contact on the patient’s leg.
Left
Figure 4-62╅ Side-posture lumbar spinous �push-pull
4-62
applied to induce right rotation at the L3-4 articulation.
Adjustment is applied in the treatment of a right rotation restriction or a left
rotation malposition at L3-L4.
event separately, resulting in an unfocused, uncoordinated thrust.
The thrust, developed through repetitive practice, is a fluid, habitual procedure, not a series of segmented and separated steps. Box
4-16 lists some basic rules and principles for the effective and safe
use of chiropractic adjustive technique.
Motion-Assisted Thrust Techniques
Right
Left
T6
T7
T8
Figure 4-61â•… Prone thoracic crossed bilateral
4-61
hypothenar transverse counterthrust technique
applied to induce left rotation at T6-7. Adjustment is applied in the treatment of a left rotation restriction or a right rotation malposition at T6-7.
Segmental contacts are established over the right T6 transverse process
and the left T7 transverse process.
Motion-assisted thrust techniques are those procedures that incorporate a component of mechanical assistance in the development
of adjustive pretension or the delivery of an adjustive thrust.
The assisting mechanical forces are typically provided by nonmotorized or motorized articulating adjustive tables. Because the
critical force necessary to preload a joint and deliver an HVLA
thrust may be difficult to achieve, the use of some form of
mechanical assistance may be desirable. In addition, some forms
of mechanically assisted technique tend to produce a long-axis
tractive force on the articulations being treated. Long-axis distractive movement is a potentially important JP component of all
synovial joints. It is not a general focus of most manually applied
techniques for the spine, although this movement is a major focus
in extremity manipulation. Incorporating it into spinal technique
may provide some additional therapeutic effect.
Mechanically assisted techniques have been postulated to
augment a practitioner’s physical attributes, allowing for the
Chapter 4â•… Principles of Adjustive Technique |
143
Box 4-16 Basic Rules for Effective Adjustive Technique
1. Select the most efficient and specific technique for the
primary problem.
2. Position the patient in a balanced, relaxed, and
mechanically efficient position.
3. The doctor should be relaxed and balanced with his or
her center of gravity as close to the contact points as
possible.
4. The contacts should be taken correctly and specifically.
5. Articular and soft tissue slack should be removed before
thrusting.
6. Any minor alterations in position or tension should be
made before thrusting.
7. Visualize the structures contacted and the direction of
your adjustive vector.
�
development
of forces that would not be otherwise achievable.
The use of drop-section table pieces or motorized moving table
sections can theoretically provide additional support for producing the needed force. Motion and mechanically assisted procedures are relatively new concepts and must be clinically studied.
Although they hold promise and are based on sound principles,
no clinical data exist to support effectiveness or efficiency. Each
of these approaches is discussed here, and specific applications are
described where applicable in Chapters 5 and 6.
Drop-Section Mechanical Assistance
The first drop headpiece was introduced in chiropractic in 1952;
B.J. Palmer stated that the principle behind the drop head piece
constituted one of the greatest advancements in chiropractic.422
Dr.€ J. Clay Thompson developed adjusting tables with cervical,
thoracolumbar, and pelvic drop-piece sections in 1957, with the
stated intention of providing a mechanical advantage for producing
an HVLA adjustment with minimal discomfort for the patient.
Dr. Thompson believed drop-table procedures used Newton’s
laws of motion to develop a certain amount of kinetic energy
not seen in other forms of chiropractic technique. He theorized
that the mechanical drop mechanism reduced the muscular effort
needed by the clinician to produce the adjustive thrust. Therefore,
the muscular strength of the clinician is not a limitation in providing manipulative therapy. Moreover, it is thought that when the
drop piece releases, the amount of force exerted on the joints is
minimal and therefore more comfortable for the patient. Finally,
because the patient cannot resist the effects of the drop sections,
it is reasoned that joint movements are more easily achieved.
Another theory proposes that the mechanical advantage gained
by drop pieces is the shear reactive force that is generated at the
termination of the drop. In this model the doctor sets more
resistance in the drop mechanism and maintains adjustive force
through the termination of the drop. There are, however, no studies
to support either of these contentions.423
The Thompson table, and all drop tables, feature mechanical drop sections that drop a small distance on the delivery of
8. Guard against the loss of established preadjustive joint
tension. Do not noticeably back off before thrusting.
9. The thrust must be delivered with optimum velocity and
appropriate depth.
10. Maintain stability and rigidity through the upper
extremities during the delivery of the adjustive thrust.
11. During the thrust, use additional body weight if
appropriate (body-drop). This is especially important in
side-posture pelvic and lumbar adjusting, in which most
of the adjustive force is derived from a body-drop thrust.
12. It is just as important to know when not to adjust as to
know when and where to adjust.
13. Primo est non nocere—First, do no harm.
Box 4-17
1.
2.
3.
4.
5.
Drop-Table Procedure
Position the body part over the drop section.
Cock the drop section, checking its tension.
Establish contacts over the part to receive the thrust.
Generate a thrusting action to make the section drop.
The thrust may be repeated to patient tolerance.
a chiropractic thrust. The amount of resistance to pressure can
be independently adjusted in each drop section. The patient is
positioned on the table with the segment to be adjusted on a
drop section with the tension properly set so that the patient’s
body weight will not cause the section to drop (Box 4-17). When
additional force is applied and the resistance of the drop section
is overcome, the section drops and terminates its fall at a preset
short distance.
Tables equipped with drop-section mechanisms have levers
used to set each drop section in a “cocked-up” position. Some
tables use a pneumatic cocking mechanism that is operated by a
foot pedal, freeing the clinician’s hands from having to locate the
levers. There are, of course, specific considerations for each joint
to be adjusted, such as the SCP, vector of thrust, and clinician
position. Specific procedures for each joint are described and demonstrated in detail in other works.424
Motorized Mechanical Assistance (Motion-Assisted
Adjusting)
Motorized mechanical traction is provided by adjusting tables that
provide continuous, rhythmic mechanical movement and distraction of the articulations to be mobilized or adjusted. Assisted
mechanical distraction of spinal joints began with manually operated tables (McManis table)425 and progressed to include tables
that provide motorized movement and distraction (Cox, Leander,
and Hill). The fundamental principle and potential advantage of
motion-assisted adjusting is the delivery of an adjustive thrust
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| Chiropractic Technique
across a joint that has been mechanically distracted. The preadjustive tension established at the involved joints is established
through the movements of the motorized table, freeing the doctor
to conserve energy and focus on his or her adjustive contacts, sense
of joint tension, and adjustive thrust.
In addition, traction tables are assumed to induce some additional long-axis distraction in the joint to which it is applied. The
movement of long-axis distraction (y-axis translation) in spinal
segments is not specifically addressed with many manipulative
approaches. In the extremity joints, considerable attention and
significance are placed on the evaluation and manual treatment
for loss of long-axis distraction and its role in producing joint
dysfunction.42,426
Using a motorized distraction table may increase the element
of long-axis distraction during manipulative treatments. Because
motion-assisted palpation and treatment may also be performed
with the patient recumbent, many different patient presentations
(e.g., acute, chronic, aged, and obese) may be accommodated by
this technique.
Most mobilization and adjustive techniques are applicable to
motorized distraction tables. Mechanized distraction tables simply
provide additional preadjustive tension and joint distraction. This
has the potential to decrease the amount of muscular effort and
force the doctor must generate to preload a joint before delivering
an adjustive thrust. When adjustive procedures are applied, segmental contacts and tissue pulls are established in the same fashion as they would be for an adjustment delivered on any adjusting
table. The adjustive thrust is typically delivered at full excursion
of the mechanized table as the doctor senses maximal distraction
of the joint.
The fundamental components of motion-assisted adjusting can
be illustrated with prone thoracic or lumbar adjustments. In the
prone positioning, the adjustive thrust is delivered as the caudal
A
section stretches. The intermittent distraction opens the involved
motion segment, facilitating the adjustment and reducing the
required force needed for the thrust. In this tractive state the
thrust can also be delivered repeatedly with less force being produced by the clinician. The table is in motion, creating distraction
of the patient with the force of the treating hands directed primarily headward. A pull-push effect is thus created along the long axis
(y-axis) of the body, facilitating the mobilization of the joint and
the restoration of long-axis distraction movement (Figure 4-63).
In addition, lateral flexion can be induced using a roll for producing prestress and a pulling vector while the table creates long axis
distraction (y-axis) movement (Figure 4-63).
The science of chiropractic has made significant strides in
the investigation of the art of chiropractic. The profession now
has a body of credible research to document some of what it
claims. Advocates of manipulative therapy in the healing arts
of chiropractic, medicine, osteopathy, and physical therapy have
independently concluded that the HVLA thrust is an important
clinical intervention for the treatment of dysfunctional conditions associated with the NMS system. The acceptance of spinal manipulation by other health care professions, industries,
and the general population continues to grow despite controversies that still exist in clinical practice. The controlled delivery
of the adjustive thrust demands much discipline and skill. An
adjustive thrust delivered incorrectly carries the risk of patient
injury. It takes extensive training and time to perfect adjustive
skills and the ability to sense and control the appropriate depth
and force of an adjustive thrust. This skill cannot be effectively
learned over the course of a few months or by attending weekend
courses. The authors hope that this chapter helps advance the
development and perfection of adjustive psychomotor knowledge and skills necessary for the delivery of safe and effective
chiropractic adjustments.
B
Figure 4-63â•… A, Diagrammatic representation of the contact point for a left lateral flexion restriction, right lateral flexion malposition, L4-L5.
B,€Motion-assisted thrust technique for intersegmental lateral flexion dysfunction (left lateral flexion restriction, right lateral flexion malposition, L4-L5).
c0025
The Spine: Anatomy, Biomechanics,
Assessment, and Adjustive Techniques
OUTLINE
STRUCTURE AND FUNCTION
OF THE SPINE
EVALUATION OF SPINAL JOINT
FUNCTION
Spinal Joint Scan
IDENTIFICATION OF JOINT
SUBLUXATION/DYSFUNCTION
SYNDROME
CERVICAL SPINE
Functional Anatomy of the
Upper Cervical Spine
Functional Anatomy of the
Lower Cervical Spine (C3–C7)
Evaluation of the Cervical Spine
Overview of Cervical Spine
Adjustments
Upper Cervical Spine
Adjustments
Lower Cervical Spine
Adjustments
145
146
147
151
152
152
157
162
170
174
180
THORACIC SPINE
Functional Anatomy
Thoracic Curve
Range and Patterns of Motion
Kinetics of the Thoracic Spine
Functional Anatomy and
Biomechanics of the
Rib€Cage
Functional Anatomy and
Characteristics of the
Transitional Areas
Evaluation of the Thoracic
Spine
Overview of Thoracic Spine
Adjustments
Overview of Rib Adjustments
THORACIC ADJUSTMENTS
Thoracocervical Adjustments
Thoracic Adjustments
Rib Adjustments
Costosternal Adjustments
STRUCTURE AND FUNCTION OF THE SPINE
The spine is, among its many other roles, the mechanism for maintaining erect posture and for permitting movements of the head,
neck, and trunk. The pelvis helps to form the foundation for posture,
and the cervical spine–occipital complex is essentially the postural
accommodation unit. The spinal column simultaneously provides
stability to a collapsible cylinder while permitting movements in all
directions. It supports structures of considerable weight, provides
attachments for muscles and ligaments, transmits weight onto the
pelvis, and encases and protects the spinal cord while allowing transmission of neural information to and from the periphery.
The functional unit of the spine, the motion segment, is the
smallest component capable of performing the characteristic roles
of the spine. The motion segment consists of two adjacent vertebrae and their associated structures. It is classically viewed as a
three-joint complex, divided into anterior and posterior elements.
The disc and vertebral bodies form the anterior joint and the two
zygapophyseal joints form the posterior joints (Figure 5-1). The
intervertebral joint is therefore a three-joint complex throughout
the spine, except for the atlanto-occipital articulation. Changes
affecting the posterior joints also affect the disc and vice versa.
The articulations of the vertebral bodies are synchondroses,
or cartilaginous joints, connected by the fibrocartilaginous intervertebral discs (IVDs). In the cervical and lumbar spines, a disc
is approximately one third of the thickness of the �corresponding
�vertebral body. In the thoracic spine, this ratio decreases to
approximately one sixth of the thickness. This articulation forms
188
188
189
189
191
191
193
195
200
211
211
211
215
226
232
Chapter
5
LUMBAR SPINE
Functional Anatomy
Lumbar Curve
Range and Patterns of Motion
Kinetics of the Lumbar Spine
Evaluation of the Lumbar Spine
Adjustments of the Lumbar
Spine
Lumbar Adjustments
PELVIC JOINTS
Functional Anatomy of the
Sacroiliac Joints
Sacroiliac Motions
Evaluation of the Pelvic
Complex
Overview of Pelvic
Adjustments
Pelvic Adjustments
Pubic Symphysis Adjustments
Coccyx Adjustments
233
233
234
235
237
238
245
253
262
262
265
266
274
274
280
281
the anterior portion of the vertebral motion unit; its chief function is weight-bearing and shock absorption.
Two important ligaments help support the vertebral bodies.
These are the anterior longitudinal ligament (ALL) and posterior
longitudinal ligament (PLL) (see Figure 5-1). The ALL extends
from the inner surface of the occiput to the sacrum. It starts as a
narrow band that widens as it descends. It is thickest in the thoracic spine and thinnest in the cervical spine. The PLL runs from
the occiput down the posterior portion of the vertebral bodies.
It is a somewhat narrow structure that has lateral extensions and
covers part of the IVD. It is also thickest in the thoracic spine and
equally thin in the cervical and lumbar regions. In the lumbar
spine, the PLL tapers, leaving the postero lateral borders of the
disc uncovered and unprotected, with important clinical ramifications. Fibers from the PLL attach to the disc itself.
The articulations between the neural arches of vertebrae are
diarthrodial joints (refered to as zygapophyseal joints, facet joints,
or posterior joints). Each has a joint cavity enclosed within a joint
capsule and lined with a synovial membrane (see Figure 5-1). The
zygapophyseal joints are true synovial joints and form the posterior portion of the vertebral motion unit. They allow a guiding,
gliding action, and the orientation of their joint surfaces is largely
responsible for determining the amount and direction of regional
spinal motions (Figure 5-2). Furthermore, the facet joints play
a significant role in load-bearing. This varies between the facets
and the disc, depending on the position of the spine. The facet
joints bear an increasing percentage of the load as the spine moves
toward an extended position.
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| Chiropractic Technique
Superior articular
process
Superior articular
facets
Posterior
longitudinal
ligament
Anterior
longitudinal
ligament
Inferior articular
process
Articular cartilage
Intervertebral
disc
Capsular
ligament
Intertransverse
ligament
Interspinous
ligament
Posterior
Anterior
A
Capsule of
zygapophyseal joint
Joint space of
zygapophyseal
joint
Transverse process
Superior articular
process
Inferior articular
process
Spinous process
B
Figure 5-1â•… Spinal motion segment composed of two vertebrae and contiguous soft tissues: intrinsic ligaments (A) and the posterior joint and joint
capsule (B). (B from White AA, Panjabi MM: Clinical biomechanics of the spine, ed 2, Philadelphia, 1990, JB Lippincott.)
Anterior tubercle
90�
45�
60�
A
B
C
Figure 5-2â•… Facet planes in each spinal region viewed from the side
and above. A, Cervical (C3–C7). B, Thoracic. C, Lumbar. (Modified
from White AA, Panjabi MM: Clinical biomechanics of the spine, ed 2,
Philadelphia, 1990, JB Lippincott.)
Support and stability for the posterior joints come from the small
segmental ligaments and the joint capsule (see Figure 5-1). The ligamentum flavum, a strong and highly elastic structure, connects adjacent lamina. The interspinous and supraspinous ligaments attach
from spinous process to spinous process. Occasionally a bursa forms
between these two ligaments. The intertransverse ligaments are relatively thin and run from �transverse process to transverse process.
Although each region of the spine has its own unique characteristics, typical vertebrae have common descriptive parts that include
a vertebral body, two pedicles, two lamina, four articular processes,
two transverse processes, and a spinous process (Figure 5-3). There
are in each region, however, atypical vertebrae, which either lack
one of these descriptive features or contain other special peculiarities. The atypical vertebrae are C1, C2, C7, T1, T9 to T12, L5, and
the sacrum and coccyx. Specific anatomic descriptions and functional characteristics are covered under each specific spinal region.
A
Pedicle
Uncinate
process
Transverse
process
Interarticular
pillar
Superior articular facet
Vertebral foramen
Lamina
Bifid spinous process
Body
Superior costal facet
Vertebral foramen
Pedicle
Costotransverse
articulate
Spinous process
Transverse
process
B
Lamina
Superior articular
process
Facet for tubercle of rib
Posterior facet joints
Body
Demifacets for
head of ribs
Spinous process
C
Superior articular
process
Transverse process
Pars interarticularis
D
Spinous process
Superior articular process
Mammillary process
Transverse
process
EVALUATION OF SPINAL JOINT FUNCTION
The investigation for spinal function incorporates history-taking;
physical examination; and, if appropriate, radiographic, laboratory,
and special examinations. The interview and examination should
be open-ended, efficient, and directed toward identifying the source
and nature of the patient’s complaint. This is not to imply that the
Foramen transversarium
Body
Pedicle
E
Body
Inferior articular
process
Spinous process
Figure 5-3â•… The structures that compose the typical cervical (A), tho-
racic (B and C), and lumbar vertebrae (D and E). (D and E from Dupuis
PR, Kirkaldy-Willis WH. In Cruess RL, Rennie WRJ, eds: Adult orthopaedics, New York, 1984, Churchill Livingstone.)
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
�
examination
should focus on just the site of complaint; the site of
complaint does not necessarily correspond to the source of the dysfunction or pathologic condition. Complaints of pain or aberrant
function may have visceral, not somatic, origin, and disorders within
the neuromusculoskeletal (NMS) system may be secondary to somatic
disease or dysfunction at distant sites. Consequently, the doctor must
develop a method to efficiently scan regions of the spine and the locomotor system for possible sites of disease or dysfunction. Within this
context, it is impractical to evaluate every joint of the musculoskeletal system during the initial evaluation. The spinal scanning examination should therefore be an abbreviated evaluation designed to
quickly scrutinize key areas of spinal joint function. Sites of potential
abnormality should then be examined in further detail to assist in the
�clinical localization of areas of potential joint dysfunction.
Spinal Joint Scan
The scanning examination of the spine is designed to screen for
alterations in structure or function indicative of possible joint subluxation/dysfunction syndromes. It incorporates the assessment of
posture, global range of motion (ROM), mobility, and the location of any sites of palpatory pain (Box 5-1).
BOX 5-1
hysical Scanning Evaluation for Joint
P
Dysfunction
Goal
To locate possible areas of joint dysfunction in need of a
further detailed examination.
Components
Posture and gait
Evaluate integration of activities of the musculoskeletal system.
Evaluate asymmetries in sectional relationships of the
spine and extremities.
Perform rapidly during initial contact with patient.
147
Posture Scan
The evaluation of static posture incorporates both lateral and
posterior assessment. The patient stands with the heels separated
approximately 3 inches and the forepart of each foot abducted
about 8 to 10 degrees from the midline.
On the lateral analysis, visible surface landmarks that ideally coincide with a plumb line are the lobe of the ear, shoulder joint, greater trochanter, and a point slightly anterior to
the middle of the knee joint and just anterior to the lateral
�malleolus (Figure 5-4).
On posterior postural examination, the plumb line should
pass through the external occipital protuberance, the spinous processes, the gluteal crease, midway between the knees, and midway between the ankles (see Figure 5-4). Look for specific postural
faults, including head tilt, head rotation, shoulder unveiling, lateral
curves of the spine, pelvic unleveling, and pelvic rotation. Postural
faults that are suspected of having a muscular basis should be followed up with evaluations of muscle length, strength, and volume.
Although there is no single ideal posture for all individuals, the
best posture for each person is the one in which the least expenditure of energy occurs because the body segments are �balanced in
the position of least strain and maximal support.
Global Range of Motion
Global ROM evaluation incorporates evaluation of all three cardinal planes of motion. Each range should be recorded and any
reduced, aberrant, asymmetric, or painful movements noted.
During a scanning examination of the spine, estimations of
range are typically conducted without the aid of instrumentation; however, inclinometric measurements may be easily incorporated. Inclinometric measurements are more reliable than
Global Range of Motion
Evaluate active movements of the cervicothoracic spine in
flexion, extension, lateral flexion, and rotation.
Evaluate active movements of the thoracolumbar spine in
flexion, extension, lateral flexion, and rotation.
Evaluate visually or quantifiably with instruments
(inclinometer or goniometer).
Motion Scan: Joint Play or Joint Challenging
Perform in the seated position (usually); posterior-to-anterior
pressure is applied to the spinal segments while the
patient’s spine is passively extended, creating a resisted
springing quality.
A fluid, wavy, rocking motion should be produced; note any
regions of restriction.
Pain scan: palpable pain or skin sensitivity.
Evaluate general areas, using light to moderate palpation or
pinwheel.
Note location, quality, and intensity of pain produced
during the previous activities.
A
B
Figure 5-4â•… Posterior (A) and lateral (B) plumb line evaluation of
posture.
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| Chiropractic Technique
A
B
Figure 5-5â•… Evaluation of skin and superficial soft tissue sensitivity and texture with light palmar contacts (A) and skin-rolling technique (B).
visual �estimates and are the standard of care in spinal impairment evaluations. The specific ranges and methods for evaluating regional mobility of the spine are discussed later under each
separate �spinal section.
Regional spinal movements that fall within normal ranges do
not necessarily exclude segmental joint dysfunction. Segmental
joint hypomobility may be masked by hypermobility at adjacent
joints.
Pain Scan
The pain scan is designed to screen for sites of possible abnormal bony or soft tissue tenderness. The superficial soft tissues are
assessed with light contacts through the palmar surfaces of the
�fingers (Figure 5-5, A) or by rolling the superficial layer between
the fingers and thumbs (Figure 5-5, B). The deeper paraspinal tissues are evaluated with the same palmar contacts, but more pressure is applied to explore the deeper layer (Figure 5-6). Particular
attention is directed to identifying any tenderness in the soft
�tissues over the posterior joints.
For evaluation of midline bony structures, the spinous processes
and interspinous spaces may be scanned with the fingertips of one
or both hands. When using a single-hand contact, the doctor rests
the middle finger in the interspinous space and the index and ring
finger on each side of the spinous process, �spanning the€ interspinous space (Figure 5-7). The middle finger palpates for interspinous spacing and tenderness, and the index and ring fingers
palpate for interspinous alignment and lateral spinous �tenderness.
When the fingers of both hands are applied, the fingertips meet
at the midline to palpate interspinous alignment and tenderness
(Figure 5-8).
The lumbar spine and thoracic spine are customarily examined
in the prone position. Although the cervical spine may be evaluated in the prone or supine position, it is more commonly evaluated in the supine position with bilateral fingertip contacts.
Motion Scan
Evaluation of spinal mobility incorporates tests to scan regional
joint play (JP), passive ROM, or end play. JP may be evaluated
with the patient in a sitting or prone position, or in the supine
Figure 5-6â•… Evaluation of the sensitivity, tone, and texture of the deep
paraspinal tissues, using the palmar surface of the fingertips.
Figure 5-7â•… Single-hand palpation of spinous process alignment and
tenderness.
position for the cervical spine. Passive ROM or EP is screened
in the sitting position or supine position in the cervical spine.
In both cases, the doctor establishes broad contacts against the
spinous processes or broad bilateral contacts over the posterior
joints. When JP is evaluated, the area evaluated should be positioned as close to the loose-packed neutral position as possible.
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
149
Figure 5-8â•… Two-hand palpation of spinous process alignment and
tenderness.
When evaluating sitting JP, the doctor sits or stands behind the
patient and places the nonpalpating arm across the patient’s shoulders (Figure 5-9) or under the patient’s flexed arms. The flexed-arm
position is commonly used in the middle to upper thoracic spine
and is developed by having the patient interlace his or her fingers
behind the neck (Figure 5-10). In the cervical spine, the indifferent
hand (IH) supports the crown of the patient’s head (Figure 5-11).
With the patient prone, the doctor establishes bilateral contacts
on each side of the spine or a reinforced contact over the spinous
processes (Figure 5-12). To scan the spine, slide up or down,
applying gentle posterior-to-anterior (P-A) springing movements.
Regions of induced pain or inappropriate movement should be
noted for further evaluation.
To screen sections of the spine for possible movement restriction, place the patient in the sitting position, with the arms crossed
over the chest. The doctor may either sit behind the patient or
stand at the patient’s side (Figure 5-13). Trunk movement is
Â�controlled by establishing contacts across the patient’s shoulder
5-9
Figure 5-9â•… Sitting joint play scan of the
thoracolumbar region.
5-10
5-11
Figure 5-10â•… Sitting joint play scan of the
midthoracic region, using the flexed-arm position.
Figure 5-11â•… Sitting joint play scan of the
�midcervical region.
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| Chiropractic Technique
B
A
5-12A, B
Figure 5-12â•… Prone joint play scan, using bilateral thenar contacts over the transverse processes (A) and reinforced hypothenar
contact over the spinous process (B).
A
B
Figure 5-13â•… A, Evaluation of left lateral flexion movement, with the doctor standing. A broad thenar contact is established along the
5-13A, B
left side of the spinous processes. B, Evaluation of left rotation movement, with the doctor seated. A broad thenar contact is established
along the left side of the spinous processes.
or by Â�reaching around to grasp the patient’s forearm. Cervical
�movement is directed by establishing a contact on the crown of the
patient’s head or forehead (Figure 5-14). These procedures are not
designed to assess JP; rather, they are applied to evaluate full ROM
with overpressure. Palpation contacts are established with the fingertips, palm, or thenar surface of the doctor’s palpation hand.
The �contacts should be broadly placed so that movement at two to
three motion segments may be scanned together.
For lateral flexion and rotation assessment of the lumbar or
thoracic region, contacts are established on the lateral surface of
the spinous processes on the side of induced rotation or laterally
bending (see Figure 5-13). In the cervical spine, the �fingertips
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151
Alignment Scan
Figure 5-14â•… Evaluation of right cervical rotation, with the doctor’s
indifferent hand contacting the patient’s forehead. The palmar surfaces
of the doctor’s right digits establish palpation contacts over the patient’s
right articular pillars.
establish the contacts over the articular pillars (see Figure 5-14).
For spinal flexion and extension, the contacts are established with
the dorsum of the hand or fingertip contacts over the interspinous
spaces of several adjacent segments (Figure 5-15). To evaluate
movement, guide the patient through the full ROM and induce
gentle overpressure at end range. During the assessment, any
regional sites of elicited pain or perceived increased or decreased
resistance should be noted. JP and regional motion scanning of
the cervical spine are commonly performed in a supine position.
A
Evaluation of joint alignment screens for asymmetric relationships on a sectional basis. Broad hand contacts are placed over
the lateral transverse processes (paraspinal region), noting any
posterior prominence indicative of rotational asymmetry. The
index and middle fingers can also scan the interspinous spaces
for widening or narrowing, indicative of flexion or extension
asymmetries.
The lumbar spine and thoracic spine are customarily examined in the prone position. Although the cervical spine may
be evaluated in the prone or supine position, it is more commonly evaluated in the supine position, using bilateral fingertip
contacts.
IDENTIFICATION OF JOINT
SUBLUXATION/DYSFUNCTION
SYNDROME
As stated previously, the goal of manual joint assessment procedures is to identify possible sites of motion segment dysfunction.
Many of the procedures used to scan the spine are also applied
in the investigation and localization of dysfunction (Box 5-2).
However, they are applied within a different context to identify
more precisely the site and nature of the dysfunction/subluxation
syndrome under question. They incorporate the detailed exploration of painful sites; the assessment of joint alignment and€the
texture, tone, and consistency of associated soft tissues; and
the€precise evaluation of intersegmental movements and end play.
B
Figure 5-15â•… Evaluation of upper lumbar flexion (A) and extension (B). The doctor’s indifferent hand contact is placed across the posterior aspect
of the patient’s shoulders while the fingertips of the palpation hand contact the patient’s interspinous spaces.
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| Chiropractic Technique
BOX 5-2
Isolation of Motion Segment
Dysfunction (PARTS)
Goal
To identify and define the specific dysfunction and specific
tissues involved.
P Pain or tenderness (location, quality, and intensity)
produced by palpation and pressure over specific
structures and soft tissues
A Asymmetry of sectional or segmental components
identified by static palpation of specific anatomic
structures
R Range of motion decrease or loss of specific movements
(active, passive, and accessory) distinguished through
motion palpation techniques
T Tone, texture, and temperature changes in specific soft
tissues identified through palpation
S Special tests or procedures linked to a technique system
The �evaluation of painful tissues often incorporates the application of various directions of applied pressure to determine the
directions of painful movement. These procedures are referred to
as joint challenging or joint provocation testing.
Neither scanning (see Box 5-1) nor isolation evaluation, alone
or in combination, constitutes a complete examination. The doctor of chiropractic must be competent in performing a complete
physical evaluation to assess the nature of the patient’s condition
and to determine if the patient is suitable for chiropractic care.
Evaluation of segmental alignment involves comparing adjacent vertebral segments for symmetry and examining inter�spinous
spaces, spinous processes, cervical articular pillars, thoracic
�transverse processes, rib angles, and lumbar mammillary processes. Sudden changes in interspinous spacing may identify flexion or extension malposition. Rotational malpositions may be
identified by misalignment of adjacent spinous processes and unilateral prominence of the cervical articular pillars, thoracic transverse processes, or lumbar mammillary processes. The articular
pillars, transverse processes, and mammillary processes are not as
distinctly palpable as the spinous processes, but they are less susceptible to congenital or developmental anomaly. Unilateral contraction of segmental muscles produces a sense of fullness and may
be mistaken for underlying rotational malposition of the articular
pillars, transverse processes, or mammillary processes.
The localization of soft tissue changes also helps in �specifying
the nature and site of joint disease or derangement. Injured or
inflamed joints may be associated with an overlying sense of
increased warmth or puffiness. Joint disease or dysfunction is also
commonly associated with local soft tissue reactive changes in the
segmentally related tissue. This may lead to sites of asymmetric
muscle tone and sites of abnormal tenderness (allodynia). Longstanding dysfunction may be associated with local areas of induration and contracture. These sites may palpate as areas of deep
nodular or rope-like consistency.
Segmental motion palpation and end-play tests are applied to
identify those segmental movements that are increased, restricted,
or painful. Pain elicited at one level and not adjacent levels helps
localize the site of possible dysfunction. Increased resistance identifies a site of possible joint fixation, and increased movement
identifies a site of possible clinical joint instability. The identification and location of soft tissue alterations, pain, and end-play
restriction are fundamental to identifying the level and the direction of possible restriction. Furthermore, they are often essential to determining the type and directions of applied adjustive
therapy.
Although all of the physical examination procedures discussed
are an integral part of joint evaluation, it must not be forgotten
that all have limitations. Many are based on the evaluation of
symmetry in structure and function, and the degree of variation
necessary to produce disease or dysfunction has not been determined. Asymmetry of structure and function is common, and
minor abnormalities in alignment and motion may be within the
range of normal variation. Furthermore, physical joint examination procedures depend on the skill of the examiner and are susceptible to errors in performance or interpretation. As discussed
in Chapters€3 and 4 the present ability to precisely identify and
adjust a �single spinal segment may be limited and not directly
related to clinical outcome. Based on this information, some have
suggested that clinicians should focus on identifying regional sites
(several segments) of dysfunction.1-4 It must also be remembered
that the identification of dysfunction does not necessarily identify
the cause.
All of these concerns lead to the necessity of incorporating outcome measures in the evaluation of patient care and contrasting all
of the history and examination findings before a diagnostic conclusion is reached and therapy is applied.
CERVICAL SPINE
The cervical spine has the precarious task of maintaining head
posture while allowing for a great deal of mobility. The cervical
spine must balance the weight of the head atop a relatively thin
and long lever, making it quite vulnerable to traumatic forces. The
cervical facets allow movement in all directions; the cervical spine
is therefore the most movable portion of the vertebral column.
The cervical spine has two anatomically and functionally distinct
regions, which are considered individually.
Functional Anatomy of the Upper
Cervical Spine
The upper cervical spine is the most complex region of the axial
skeleton. It is composed of the atlanto-occipital and atlantoaxial articulations, which serve as a transition from the skull to the
rest of the spine. These two functional units are anatomically and
kinematically unique. Neither has an IVD, and the atlantoaxial
articulation incorporates three synovial joints.
The atlas has no vertebral body or spinous process (Figure 5-16).
It consists of a bony oval, with the two lateral masses �connected
by the anterior and posterior arches. The lateral masses, formed
from enlarged pedicles, have concave articular facets superiorly for
articulation with the occipital condyles and circular �inferior facets
for articulation with the axis.
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
Anterior tubercle
Articular facet
Anterior arch of atlas
Transverse
process
Transverse
foramen
Odontoid
process
Transverse
ligament
Posterior arch
Figure 5-16â•… The structure of the atlas (C1).
Odontoid process
153
Super articulating
facet
Lateral
mass
Figure 5-18â•… The atlanto-odontoid articulation viewed from above.
Transverse
foramen
Foramen magnum
POSTERIOR
ANTERIOR
Occipital
condyle
Vertebral
body
Spinous process
Superior
articular
surface
Transverse
process
Figure 5-17â•… The structure of the axis (C2).
The outstanding feature of the axis (C2) is the presence of the
odontoid process (dens) (Figure 5-17). The odontoid is formed by
the fusion of the embryologic remnants of the vertebral body of
the atlas to the superior aspect of the body of the axis. The€spinous
process of the axis is large and bifid, and it is the first palpable
midline structure below the occiput. The superior articular surfaces project from the superior aspect of the pedicles to meet the
inferior aspects of the atlas’ lateral masses. Their surfaces are convex and lie in the transverse plane, with a slight downward lateral
slant. The atlantoaxial articulation is formed by articular surfaces
of the C1–2 lateral masses. Both articular surfaces are convex,
allowing for considerable mobility in rotation. The atlanto-odontal articulation is formed by the anterior arch of the atlas and the
odontoid process. The odontoid process is completely surrounded
by the anterior arch of the atlas anteriorly, the lateral masses laterally, and the transverse ligament posteriorly (Figure 5-18). It is a
trochoid joint, providing a pivot action.
The atlanto-occipital articulation is a freely movable synovial
condyloid articulation (Figures 5-19 and 5-20). The articular
�surfaces of the condyles are convex and converge anteriorly, resembling curved wedges that fit into matching concave surfaces in the
lateral masses of the atlas. Individual axes for each condyle exist,
Figure 5-19â•… The atlanto-odontoid articulation has convex occipital
condyles that fit into the concave lateral masses of the atlas.
Occipital
condyle
Lateral
mass
Axis
Figure 5-20â•… A coronal section through the atlanto-occipital and
atlantoaxial articulations, showing the plane of the facets.
demonstrating that there is no single axis for axial rotation. The
axis of movement for rotation occurs at two points �(eccentrically
located), thus resulting in very little active rotation. Each condyle
can move a degree or two forward and backward without the other
side moving much.
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| Chiropractic Technique
Rectus capitis posterior minor
Rectus capitis
posterior major
Rectus capitis
posterior minor
Obliquus capitis superior
Rectus capitis
posterior major
Obliquus capitis inferior
Rectus
capitis anterior
Longus capitis
Obliquus capitis
superior
Figure 5-22â•… Lateral view of the suboccipital muscles.
Obliquus capitis
inferior
A
Rectus capitis anterior
Rectus capitis
lateralis
Longus capitis
B
Figure 5-21â•… The suboccipital muscles. A, Posterior view.
B, Anterior view.
The muscles that provide the forces necessary for movement,
postural support, and primary stability of the upper cervical region
include the rectus capitis posterior major, rectus capitis posterior minor, rectus capitis lateralis, rectus capitis anterior, superior
oblique, and inferior oblique (Figures 5-21 and 5-22). All of these
muscles are supplied with motor fibers from the first cervical nerve
and proprioceptive and pain fibers via a communicating branch
from the second cervical nerve.
The ligaments that provide added stability to the upper cervical
spine include the transverse ligament of the atlas, alar ligaments,
PLL, posterior atlanto-occipital membrane, anterior atlanto-
occipital membrane, ligamentum nuchae, and the apical ligament
(Figure 5-23). Because the ligaments of the upper cervical spine
can be damaged by trauma, weakened by systemic inflammatory
diseases, or congenitally absent or malformed, testing for their
integrity should be done before manipulative therapy is begun. If
instability is suspected, flexion-extension stress x-ray examinations
should be performed.
Range and Pattern of Motion of C0–C1
The principle movement that occurs in the atlanto-occipital
articulation is flexion and extension.5 The combined range is
approximately 25 degrees (Table 5-1 and Figure 5-24). Flexion
and extension movements at C0–1 are predominantly angular
movements in the sagittal plane, without any significant associated coupled motions. During flexion the occipital condyles glide
posterosuperiorly on the lateral masses of the atlas as the occipital bone separates from the posterior arch. During �extension,
the€ condyles slide anteriorly on the lateral masses of the atlas
while the occipital bone approximates the posterior arch of atlas
(Figure 5-25).
Axial rotation at the C0–1 articulation was previously
thought to be very limited.6 However, recent studies have demonstrated a range of 4 to 8 degrees to each side.5 Rotational
movement is limited by the articular anatomy and the connections of the alar ligaments. The movement that does occur is
predominantly in the elastic range at the end of total cervical
rotation, where it is usually coupled with some small degree of
lateral flexion.7
Lateral flexion of the atlanto-occipital articulation approximates that of axial rotation. Although the articular design of the
atlanto-occipital articulation should allow for greater flexibility in
Apical ligament
Alar ligaments
Occiput
Superior longitudinal band
of cruciate ligament
Cruciate
ligament
Atlas
Transverse ligament
of atlas
Inferior longitudinal band
of cruciate ligament
Accessory alantoaxial
ligaments
Axis
Posterior longitudinal
ligament
Figure 5-23â•… Upper cervical spinal ligaments shown with the posterior arch of the atlas and axis removed.
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TABLE 5-1
155
Segmental Range of Motion for the Upper Cervical Spine
Vertebra
Combined Flexion and Extension
One-Side Lateral Flexion*
One-Side Axial Rotation
C0–1
C1–2
25 degrees
20 degrees
5 degrees
5 degrees
5 degrees
40 degrees
*Lateral glide or translation (laterolisthesis) occurs with lateral flexion movements of the neck.
Modified from White AA, Panjabi MM: Clinical biomechanics of the spine, ed 2, Philadelphia, 1990, JB Lippincott.
Cervical
C2 – C3
C4 – C5
C6 – C7
Thoracic
T1–T2
T3 –T4
T5 –T6
T7–T8
T9 –T10
T11–T12
Lumbar
C0 – C1
L1– L2
L3 – L4
L5–S1
Posterior view
Occiput
C1
Alar
ligaments
C2
Transverse
ligament of
atlas
A
Left bending of head
0° 5° 10° 15° 20° 25°
5° 10° 15°
Combined
One side
flexion/extension
lateral bending
(� x-axis rotation) (z-axis rotation)
5° 10° 15° 35° 40°
One side
axial rotation
(y-axis rotation)
Figure 5-24â•… Representative values for rotatory range of motion at
each level of the spine. (From White AA, Panjabi MM: Clinical biomechanics of the spine, ed 2, Philadelphia, 1990, JB Lippincott.)
Occiput
C1
C2
B
Figure 5-26â•… The role of the alar ligaments in lateral flexion of the
atlanto-occipital articulation. A, Posterior view in the neutral position. B,
Left lateral flexion. Motion is limited by the right upper portion and the
left lower portion of the alar ligaments.
A
B
Figure 5-25â•… Flexion (A) and extension (B) of the occiput-atlas and
atlas-axis.
lar surface during lateral flexion are coronal plane rotation (roll)
and translation (slide). Roll and slide occur in opposite directions
because of the convex shape of the occipital condyles and the concave shape of the atlas articular surface. Rotation (roll) occurs in
the direction of lateral flexion, and translation (slide) occurs in the
direction opposite the lateral flexion (Figure 5-27).
The instantaneous axes of rotation (IAR) have not been experimentally determined for the atlanto-occipital articulation. The
axes were estimated “by determining the centers of the arches
formed by the outline of the joints in the sagittal and frontal
planes”5 (Figure 5-28).
Range and Pattern of Motion of C1–2
lateral flexion, it appears that the attachments of the alar ligament
function to limit this motion (Figure 5-26). Movement occurs primarily in the coronal plane, although it is typically associated with
some small degree of coupled rotation in the opposite direction.
This leads to rotation of the chin away from the side of lateral
flexion. The predominant movements occurring at the articu-
The principal movement that occurs at the atlantoaxial joint is
axial rotation. Segmental range averages 40 degrees to each side,
contributing to more than half of the total cervical rotation.
The first 25 degrees of cervical rotation occur primarily in the
�atlantoaxial joint.7 During rotation the lateral mass and articular surface slide posteriorly on the side of rotation and anteriorly
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| Chiropractic Technique
Rotation of C1
IAR
L
R
Figure 5-27â•… Right lateral flexion of the atlanto-occipital articulation,
demonstrating rolling of the occiput to the right (solid arrow) and sliding
to the left (broken arrow).
C2
Figure 5-29â•… The theoretic location of the instantaneous axis of rotation for the atlantoaxial articulation in axial rotation.
R
A
L
E
Neutral
F
Rotation
B
Figure 5-28â•… The theoretic location of the instantaneous axes of rota-
tion for the atlanto-occipital articulation (dot) in lateral flexion (R and€L)
(A) and flexion (F) and extension (E) (B). (From White AA, Panjabi
MM: Clinical biomechanics of the spine, ed 2, Philadelphia, 1990, JB
Lippincott.)
on the side opposite rotation. The motion occurs about a centrally located axis within the odontoid process (Figure 5-29). An
�additional subtle vertical displacement of the atlas takes place
with rotation as a result of the biconvex structure of the articular
�surfaces (Figure 5-30).
Flexion and extension movements of the atlas on the axis occur
as rocking movements as a result of the biconvex facet surfaces.
The IAR is located in the middle third of the dens. In flexion, the
posterior joint capsule and posterior arches separate, and the atlas
articular surface glides forward. In extension, the posterior joint
capsule and posterior arches approximate, and the atlas articular
surface glides posteriorly (Figure 5-31). Also, the anterior arch
of the atlas must ride up the odontoid process during extension
and down during flexion. Flexion and extension movements of
the atlantoaxial joint are also associated with small translational
movements from 2 to 3 mm in the adult up to 4.5â•›mm in the
child.5 Any movement greater than these ranges should trigger an
evaluation to assess the stability of the C1–2 articulation and the
integrity of the odontoid and transverse ligaments.
Compared with rotation, lateral flexion of the atlantoaxial articulation is limited, averaging approximately 5 degrees to each side.7
It has been suggested that lateral flexion is coupled with translation; however, this is a controversial subject.5 The associated translation is purported to occur toward the side of lateral flexion. In
Figure 5-30â•… Because the articular surfaces are both convex, as the
atlas rotates on the axis, a subtle vertical displacement occurs, causing the
two segments to approximate one another.
A
B
Figure 5-31â•… Flexion (A) and extension (B) of the atlanto-axial joint.
other words, right lateral flexion of the cervical spine would be
associated with translation of C1 to the right (Figure 5-32).
Further clouding the issue is the apparent translation that
may be visible on an anterior-to-posterior open-mouth (APOM)
radiograph with rotational subluxation of the atlas. Rotational
�movement of the lateral masses about the odontoid process may
induce an apparent lateral translation of the atlas on the APOM
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157
Uncinate processes
Transverse
foramen
Body
Transverse
process
Pedicle
Superior facet
Inferior facet
Vertebral foramen
Articular process
Lamina
Spinous process
Figure 5-34â•… Structure of a typical cervical vertebra.
L
R
Figure 5-32â•… Right lateral flexion of the upper cervical spine (solid
arrow) with translation of the atlas (broken arrow) toward the right.
From
above
Openmouth
view
Joints of
Von Luschka
AP
openmouth
view
Right rotation
of atlas
Neutral
Left rotation
of atlas
Figure 5-33â•… Atlas rotation produces a wider lateral mass and narrower
appearance of the atlanto-odontal interspace on the side of posterior rotation.
This may lead to a false impression of a lateral flexion or translational malposition of the atlas on the anterior-to-posterior open-mouth radiograph.
Figure 5-35â•… The uncinate processes limit pure lateral flexion to only a
few degrees while serving as guides to couple lateral flexion with rotation.
radiograph as a result of projectional widening and narrowing of
the lateral masses (Figure 5-33).
Functional Anatomy of the Lower
Cervical Spine (C3–C7)
The typical cervical vertebrae (C3–C6) possess the same structural
parts as all other true vertebrae, plus some unique and �distinctive
physical features (Figure 5-34). The spinous processes are bifid
to allow for better ligamentous and muscular attachment. Each
transverse process from C6 upward contains the transverse foramen, allowing for the passage of the vertebral artery. The body
of the typical cervical vertebra has anterior and posterior surfaces
that are small, oval, and wide transversely. The anterior and posterior surfaces are flat and of equal height. The posterior lateral
aspect of the superior margin of the vertebral bodies is lipped,
forming the uncinate processes, which serve to strengthen and
stabilize the region. The uncovertebral articulations (joints of
Von Luschka) are pseudojoints that have a synovial membrane
with synovial fluid but no joint capsule (Figure 5-35). They serve
as tracts that guide the motion of coupled rotation and lateral
�
flexion.
They begin to develop at 6 years of age and are complete
by 18 years of age.
The articular facets are teardrop-shaped, with the superior facet
facing up and posteriorly and the inferior facet facing down and
anteriorly, placing the joint space at a 45-degree angle midway
between the coronal and transverse planes (Figure 5-36). The disc
height–to–body height ratio is greatest (2:5) in the cervical spine,
therefore allowing for the greatest possible ROM (Figure 5-37).
The short and rounded pedicles of cervical vertebrae are directed
posterolaterally. The superior and inferior vertebral notches in each
pedicle are the same depth. The laminae are long, narrow, slender,
and sloping. The intervertebral foramina in this region are larger
than in the lumbar or thoracic areas and are triangular in shape.
The C7 vertebra (vertebra prominence) is considered the atypical segment of the lower cervical spine. It demonstrates anatomic
characteristics of both the cervical vertebra and the thoracic vertebra. It has a spinous process that is quite long and slender, with
a tubercle on its end. The inferior articular processes are similar
to those in the thoracic spine, and the superior processes match
those of the typical cervical vertebra. C7 has no uncinate processes
and no transverse �foramen. The transverse processes are large,
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| Chiropractic Technique
Spinous process
Lamina
Articular process
Superior articular
facet
Transverse
process
Pedicle
Vertebral body
Figure 5-38â•… The structure of the C7 vertebra (vertebral prominence).
45�
Figure 5-36â•… The cervical facet planes, demonstrating a 45-degree
angle to the horizontal plane.
Gravity
W
Center skull mass
External occipital
protuberance
Atlas center mass
Capitis muscle
effort
2:5
C4 center mass
C5 center mass
T1 center mass
4
3
10
3
Figure 5-37â•… The location of the nucleus pulposus and the disc
height–to–body height ratio in the cervical spine.
broad, and blunt. The transverse processes may become enlarged
or develop cervical ribs, with the potential to create thoracic outlet
compromise (Figure 5-38).
Cervical Curve
The cervical spine forms a lordotic curve that develops secondary
to the response of upright posture. The functions of the cervical
curve and the anterior-to-posterior (A-P) curves throughout the
spine are to add resiliency to the spine in response to axial compression forces and to balance the center of gravity of the skull
over the spine. The center of gravity for the skull lies anterior to
the foramen magnum (Figure 5-39).
The facet and disc planes in large part determine the degree of
potential lordosis. Congenital diversity in pillar height and facet
Resultant vector
Figure 5-39â•… The center of gravity for the skull. If the cervical curve
changes, the center of gravity shifts.
angulation therefore leads to significant variation in the degree of
cervical lordosis present in the population. In addition, degenerative changes or stress responses in these structures may change the
“normal” lordosis.
There are a number of opinions as to what the normal cervical
curve should be and how it should be measured.6,8-14 There is also
significant debate on what constitutes an abnormal curve and what
biomechanical consequences, if any, will result from alteration in
the cervical lordotic curve. A reduced cervical curve (hypolordosis)
has the potential to shift more weight onto the vertebral bodies and
discs and increase muscular effort as the posterior neck muscles
work to maintain head position and spinal stability. An increased
cervical curve (hyperlordosis) will potentially increase the compressive load on the facets and posterior elements (Figure 5-40).
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159
1
2
1
3
4
5
2
2
3
3
4
4
5
5
6
6
7
6
1
1
2
3
7
4
T1
7
T2
A
B
C
Figure 5-40â•… The cervical curve extending from C1 to T2. A, Normal.
5
mm measurement
B, Hypolordosis with a kyphosis involving the middle segments. C, Alordotic.
6
7
Figure 5-42â•… Jochumsen’s measuring procedure for determining the
adequacy of the cervical curve.
1
2
30� 45�
60�
3
Radius
4
Arc
Chord
60�
5
6
60�
Radius
7
Radius � Chord
Figure 5-41â•… The angle of the cervical curve should be about 30 to 45
Figure 5-43â•… Diagram demonstrating the relationship formed when a
Various methods for radiographically measuring lordosis have
been suggested. The most common method involves direct measurement of the curve by forming an angle between a line extending through the center of C1, with a line drawn along the inferior
endplate of C7 (Figure 5-41). Although the cervical lordosis
apparently extends to the T1–2 motion segment, measurements
commonly use the C7 level as the lowest point reliably viewed
on a lateral cervical x-ray film. Another method presented by
Jochumsen12 proposes classifying the cervical curve by measuring
the distance from the anterior body of C5 to a line running from
the anterior arch of the atlas to the anterior superior aspect of the
body of C7 (Figure 5-42). There is some agreement that the cervical curve midpoint is the C5 vertebra (C4–5 interspace).
The proposed optimal curve for the cervical spine can be extrapolated from the mechanical principle that states the �strongest
and most resilient curve is an arc that has a radius of curvature
equal to the cord across the arc (Figure 5-43). The length of the
radius, and hence the cord, should equal approximately 7 inches
or 17â•›cm. As the radius increases, the curve increases (flattens, as
in hypolordosis) and vice versa.
degrees when measured between lines drawn through C1 and C7.
chord equals the radius of an arc.
Range and Pattern of Motion of the Lower
Cervical Spine
The lower cervical spine exhibits its greatest flexibility during flexion
and extension movements (Table 5-2; see Figure 5-24). Lateral flexion
exhibits slightly greater movement than rotation. Both rotation and
lateral flexion decrease significantly at the thoracocervical junction.
Flexion and Extension. Movement averages approximately
15 degrees of combined flexion and extension per segment and
is greatest at the C5–6 motion segment.15 Flexion and extension
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| Chiropractic Technique
TABLE 5-2
Segmental Range of Motion for the Lower Cervical Spine*
Vertebra
Combined Flexion and Extension
One-Side Lateral Flexion
One-Side Axial Rotation
C2–3
C3–4
C4–5
C5–6
C6–7
C7–T1
5 to 16 (10) degrees
7 to 26 (15) degrees
13 to 29 (20) degrees
13 to 29 (20) degrees
6 to 26 (17) degrees
4 to 7 (9) degrees
11 to 20 (10) degrees
9 to 15 (11) degrees
0 to 16 (11) degrees
0 to 16 (8) degrees
0 to 17 (7) degrees
0 to 17 (4) degrees
0 to 10 (3) degrees
3 to 10 (7) degrees
1 to 12 (7) degrees
2 to 12 (7) degrees
2 to 10 (6) degrees
0 to 7 (2) degrees
*Numbers in parentheses indicate averages.
Modified from White AA, Panjabi MM: Clinical biomechanics of the spine, ed 2, Philadelphia, 1990, JB Lippincott.
IAR
IAR
A
B
Figure 5-44â•… Sagittal plane movement of a cervical motion segment
in flexion (A) and extension (B), locating the instantaneous axis of rotation and the stair-stepping appearance that occurs with combined tipping
and gliding movements.
occur around an axis located in the subjacent vertebra and combine sagittal plane rotation with sagittal plane translation (Figure
5-44). This pattern of combined segmental angular tipping and
gliding develops a stairstep effect, which is noted on flexion and
extension radiographs.
With flexion, the articular joint surfaces slide apart, producing stretching of the facet joints and posterior disc and anterior
disc approximation and compression. With extension, the opposite occurs. The disc is subjected to compression on the concave
side and tension on the convex side. The side of the disc subjected to tension retracts and the side subjected to compression
bulges.5 The net effect of these two opposing forces is to limit
shifting of the nucleus pulposus during movements of flexion and
extension and lateral flexion (Figure 5-45). Krag and colleagues16
implanted small metal markers within the lumbar and thoracic
IVDs and confirmed the bulging and retraction of the discs during lumbar segmental flexion movements. However, they did note
some minor posterior migration of the nucleus that was not identified by previous mathematical models. This phenomenon has
not been investigated for the cervical spine.
The coupled translation that occurs with flexion and extension
has been measured at approximately 2â•›mm per segment, with an
upper range of 2.7â•›mm.17 Translational movements do not occur
evenly throughout the cervical spine.15 For every degree of sagittal plane rotation, more translation occurs in the upper cervical
segments than in the lower cervical segments. This leads to a flatter arch of movement in the upper cervical spine (Figure 5-46).
Accounting for radiographic magnification, White and Panjabi5
C2
Tension
Compression
C7
Instantaneous
axis of rotation
Figure 5-45â•… Representation of changes in the disc with flexion, as
well as extension, or lateral flexion movements.
Figure 5-46â•… With active flexion and extension movements, more
translation takes place in the upper segments than the lower segments,
leading to a flatter arc of movement.
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
Flexion and
Extension
Lateral
Bending
E
F
R
E
F
161
Axial
Rotation
L
R
?
L
L�R
Figure 5-47â•… The theoretic locations for the instantaneous axis of rotation for each plane of movement in the lower cervical spine. (From White AA,
Panjabi MM: Clinical biomechanics of the spine, ed 2, Philadelphia, 1990, JB Lippincott.)
Figure 5-49â•… Illustration of segmental left rotation coupled with
�normal left lateral flexion.
A
B
Figure 5-48â•… A, Left lateral flexion coupled with physiologic left
�rotation. B, Movement of the facet surfaces with left lateral flexion and
coupled left rotation in the lower cervical spine.
have recommended 3.5â•›mm as the upper end of normal translational movement in the lower cervical segments. Translation
beyond 3.5â•›mm suggests end range segmental instability.
Lateral Flexion. Lateral flexion averages approximately 10
degrees to each side in the midcervical segments, with decreasing
flexibility in the caudal segments. The IAR for lateral flexion has
not been determined. Speculation places the axis in the center of
the subjacent vertebral body (Figure 5-47).
Lateral flexion in the lower cervical spine is coupled with
rotation in the transverse plane. The coupling is such that lateral flexion and rotation occur to the same side. This leads to
posterior vertebral body rotation on the side of lateral flexion,
thereby �causing the spinous processes to deviate to the convexity
of the curve (Figure 5-48). The degree of coupled axial rotation
decreases in a caudal direction.14 At the second cervical vertebra there are 2€ degrees of coupled rotation for every 3 degrees
of lateral bending, and at the seventh cervical vertebra there is
only 1 degree of coupled rotation for every 7.5 degrees of lateral
bending.
During lateral flexion the facets on the side of lateral flexion
(concave side) slide together as the inferior facet slides inferomedially because of the coupled rotation. On the opposite side, the
facets distract and the inferior facet slides superiorly. The IVD
approximates on the side of lateral flexion and distracts on the
opposite side.
Rotation. ROMs for segmental axial rotation on average are
slightly less than those for lateral flexion, with a similar tendency
for decreased movement in the lower cervical segments, especially at the C7–T1 motion segments. The axis of rotation is also
�somewhat speculative and has been placed by Lysell14 in the anterior subjacent vertebral body (see Figure 5-47).
Rotational movements in the lower cervical spine demonstrate
the same coupling as described for lateral flexion. In other words,
left or right axial rotation is coupled with lateral flexion to the
same side. This leads to a pattern of motion in which, on the side
of cervical rotation (posterior body rotation), the inferior facet of
the superior vertebra glides posteroinferiorly as the contralateral
glides anterosuperiorly (Figure 5-49).
Cervical Kinetics
Nonsegmental muscles produce integrated global movement of
the cervical spine as a result of the head’s moving in relation to
the trunk. Concentric and eccentric muscle activity is combined,
with eccentric activity predominating during flexion, extension,
and lateral flexion. Concentric muscle activity refers to the development of sufficient muscle tension to overcome a resistance,
causing the muscle to visibly shorten and the body part to move.
However, eccentric muscle activity occurs when a given resistance
overcomes the muscle tension, causing the muscle to actually
lengthen. Relaxation of a muscle against the force of gravity, creating a deceleration of the moving body part, is an example of
eccentric muscle activity.15
The segmental (intrinsic) muscles function to coordinate and
integrate segmental motion. The intrinsic muscles act as involuntary integrators of overall movement. Movements of the head initiate normal movements of the cervical spine, but with conscious
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| Chiropractic Technique
effort, movement may be initiated at lower segmental �levels. They
operate by the same concentric and eccentric principles as the
larger nonsegmental muscles.
Flexion is initiated by anterior cervical muscles and controlled
or limited by eccentric activity of the semispinalis, longissimus,
and splenius muscle groups. Flexion is further limited by the
�elastic limits of myofascial tissue, nuchal ligament, joint capsule,
PLL, ligamentum flavum, posterior IVD, anterior vertebral bodies, and the chin hitting the chest.
Posterior cervical muscles controlled or limited by the eccentric activity of the sternocleidomastoid (SCM), scaleni, and longus coli muscle groups initiate extension. Extension is further
limited by the elastic limits of the myofascial tissue, anterior
IVD, ALL, joint capsule, posterior vertebral bodies, and articular pillars.
Lateral flexion is initiated by ipsilateral contraction and controlled or limited by the contralateral eccentric activity of the splenius capitis, semispinalis cervices, and longus coli muscle groups.
Lateral �flexion is further limited by the elastic limits of some myofascial tissue, contralateral joint capsule, periarticular ligaments,
flaval ligament, IVD, ipsilateral joint capsule, and ipsilateral
�articular pillars.
Rotation is initiated by concentric contraction of the ipsilateral splenius capitis and cervicis, longissimus cervicis, and contralateral semispinalis muscles. Eccentric muscle contraction occurs
simultaneously to guide and break movements and involves action
of the contralateral splenius capitis, cervicis, longissimus cervicis,
and ipsilateral semispinalis and scaleni muscles. Movement is further limited by capsular and periarticular ligaments and �segmental
muscles.
Evaluation of the Cervical Spine
Observation
Examination of the cervical spine begins with a visual examination of the alignment and ROM of the cervical spine in the sagittal, coronal, and transverse planes. Alignment in the coronal plane
is evaluated by observing the orientation of the head relative to
the trunk and shoulders, the leveling of the mastoid processes,
and the€symmetry of the cervical soft tissues. Observing the status
of the cervical curve and orientation of the patient’s chin assesses
sagittal plane alignment. Tucking or elevation of the chin in the
presence of a normal cervical curve may indicate upper cervical
dysfunction. Observing the patient from the posterior and noting
any turning of the head (Figure 5-50) may assess orientation of the
head in the transverse plane.
Global ROM is most effectively evaluated in the sitting
�position. Take care to observe for recruitment of trunk movement and stabilize the shoulders if necessary. During flexion the
patient should be able to touch the chin to the chest, and during
extension look straight toward the ceiling. During rotation the
patient should be able to approximate the chin to the shoulder,
and during lateral flexion approximate the ear to within two to
three fingers’-width of the shoulder (Figure 5-51). Variations with
sex and age are quite common. If ROM is evaluated in circumstances other than screening evaluations, it should be conducted
A
B
C
D
E
Figure 5-50â•… Common cervical postural presentations. A, Normal.
B, Occiput in left posterior rotation. C, Occiput in right lateral flexion or
atlas in left laterolisthesis. D, Atlas in right rotation. E, Axis in rotation
and right lateral flexion. (Modified from Pratt NE: Clinical musculoskeletal anatomy, Philadelphia, 1991, JB Lippincott.)
with the use of inclinometry for more accurate recordings of the
ranges (see Figure 3-11 and Table 5-3).
Static Palpation
Palpation for alignment, tone, texture, and tenderness of the bony
and soft tissue structures of the neck is conducted with the patient
in the supine or sitting position. During supine evaluation, stand
or kneel at the head of the table, and during the seated evaluation,
stand behind the patient.
Upper Cervical Spine. The suboccipital muscles are evaluated
by using the palmar surfaces of the fingertips to make a bilateral
comparison of tone, texture, and tenderness (Figure 5-52). Bony
alignment of the atlanto-occipital joint is evaluated by placing the
tip of the index finger in the space between the mandibular ramus
and the anterior tip of the atlas transverse process and between the
inferior tip of the mastoid process and the atlas transverse process
(Figure 5-53).
Spacing between the atlas transverse process and the
mandibular ramus and between the atlas transverse process
and mastoid processes should be symmetric on both sides.
Malpositions between C0 and C1 can affect the spacing
between the mandibular ramus and the C1 transverse process.
The space between the angle of the jaw and atlas transverse
processes may be closed on the side of posterior occipital rotation and open on the contralateral side. With lateral flexion,
the mastoids may be unlevel, and a decreased spacing may be
noted in the interspace between the atlas transverse process
and mastoid process.
Bony alignment of the atlantoaxial joint is evaluated by comparing the relative alignment of the atlas transverse processes
and axis articular pillars. This is accomplished by establishing
bilateral contacts with the doctor’s index and middle fingers
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163
B
A
D
C
Figure 5-51â•… Cervical global range of motion. A, Flexion. B, Extension. C, Right lateral flexion. D, Left rotation.
TABLE 5-3
lobal Range of Motion for the
G
Cervical Spine
Motion
Normal
Range
Range Without
Impairment
Flexion
Extension
Lateral flexion
Rotation
60–90 degrees
75–90 degrees
45–55 degrees
80–90 degrees
60 degrees
75 degrees
45 degrees
80 degrees
Figure 5-52â•… Palpation of suboccipital muscle tone and texture.
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| Chiropractic Technique
A
B
Figure 5-53â•… Palpation for flexion, extension, or rotation alignment (A) and lateral flexion alignment of the atlanto-occipital articulation (B).
Figure 5-54â•… Palpation for rotation and lateral flexion alignment of
the atlanto-axial articulation.
over each structure (Figure 5-54). Posterior prominence of the
atlas or palpable stair stepping of the atlas and axis transverse
processes indicates possible rotational malposition of the atlas.
Lateral prominence of the atlas or narrowing of the lateral atlasaxis interspace indicates possible lateral flexion malposition of
the atlas.
Asymmetry in suboccipital muscle tone and tender and taut
suboccipital muscles are further indications of possible upper
�cervical joint dysfunction. However, the upper cervical spine is
at the end of a kinetic chain, and asymmetries in tone and alignment are commonly encountered. They may be normal variations
or sites of compensational adaptation instead of primary joint
dysfunction.
Lower Cervical Spine (C2–C7). Palpating the spinous process,
interspinous spaces, and posterior articular pillars assesses bony
contour, tenderness, and alignment. In the sitting position, the
interspinous spaces may be palpated with the middle finger while
the index and ring fingers lay along the lateral �margins to compare
alignment of adjacent spinous processes (Figure 5-55). The spinous
processes are bifid and difficult to palpate in the �midcervical spine.
They become more accessible if the neck is placed in a slight flexion. The articular pillars are not as accessible to direct palpation
but are probably a more reliable landmark for detecting rotational
malpositions.
Figure 5-55â•… Palpation for the alignment of the spinous processes in
the lower cervical spine.
Figure 5-56â•… Palpation for the alignment of the articular pillars in the
midcervical spine.
To evaluate the alignment of the articular pillars and the tone,
texture, and tenderness of the paraspinal soft tissues, establish segmental contacts on each side of the spine. If the patient is in the
sitting position, use the thumb and index fingers (Figure 5-56); if
the patient is in the supine position, use the palmar surfaces of the
fingers of both hands to make a �bilateral comparison.
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Motion Palpation
Cervical JP, segmental ROM, and end play may be evaluated with
the patient in either a sitting or a supine position. Stand behind
the seated patient or sit, kneel, or squat at the head of the table
during a supine evaluation.
Joint Play. To evaluate JP and P-A glide with the patient in
the seated position, position the patient’s neck in a neutral position and establish segmental contacts bilaterally over the posterior
joints, with the palmar surfaces of the index finger and thumb.
With the patient’s forehead supported by the IH, gently spring
each individual motion segment in a fluid P-A gliding motion
along the horizontal plane (Figure 5-57).
In the supine position, the doctor assesses P-A glide by contacting
the posterior joints with the palmar surfaces of the fingertips. The
patient’s head rests on the table while the fingertips spring posteriorly
to anteriorly against the articular pillars (Figure 5-58). Contact the
posterolateral surface of adjacent vertebrae with the radial or palmar
5-57
165
surface of the doctor’s index fingers to assess lateral-to-medial (L-M)
glide. Testing is performed by springing toward the midline with one
hand as the other hand counterstabilizes (Figure 5-59).
During P-A JP assessment, the doctor should feel a subtle gliding and recoil at each segment tested. The movement should be
uniform on each side and pain free; unilateral resistance or a tendency for the spine to rotate out of the sagittal plane may indicate
segmental dysfunction. L-M glide is less giving than A-P glide,
and a perceptible decrease in movement should be noted when the
adjacent vertebra is counterstabilized. Excessive sponginess and
lack of elastic resistance with either procedure indicates �possible
hypermobility or instability.
Segmental Range of Motion and End Play (C0–1)
C0–1 Flexion and Extension. Atlanto-occipital flexion and
extension may be evaluated by placing the tip of the index finger
in the space between the mandibular ramus and the anterior tip
of the atlas transverse process. The doctor’s IH supports the top of
the head in the sitting position and cups the patient’s contralateral
occiput and mastoid in the supine position. The patient’s chin is
elevated and tucked to instill extension and flexion in the upper
cervical spine. The space between the mandibular ramus and
atlas transverse process opens during extension and closes �during
�flexion (Figure 5-60). Fixation in this plane leads to a loss of rolling of the occiput on the atlas and unchanged spacing between the
angle of the jaw and the atlas transverse process.
To evaluate end play, apply additional springing overpressure
at the end ROM. For flexion, the contacts are established under
the inferior rim of the occiput, with pressure applied upward.
Figure 5-57â•… Sitting joint play evaluation for
posterior-to-anterior glide in the midcervical spine.
Figure 5-58â•… Supine joint play evaluation for posterior-to-anterior
glide in the midcervical spine.
Figure 5-59â•… Supine joint play evaluation for lateral-to-medial glide.
The doctor contacts adjacent levels and applies medial-to-lateral pressure
with the cephalad hand as the caudad hand counterstabilizes.
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| Chiropractic Technique
A
Figure 5-60â•… Palpation for extension movement of the right atlantooccipital articulations.
B
5-61A, B
5-62
Figure 5-62â•… Palpation of left rotation at the atlantooccipital articulation.
For extension, the contacts are established over the mastoid and
�posterior occiput, with pressure applied forward and downward
(Figure 5-61). Flexion end play has a firmer quality because it is
limited by the strong posterior neck muscles.
C0–1 Rotation (P-A glide). The index finger is placed between
the mandibular ramus and the anterior tip of the atlas transverse �process. The head is passively rotated away from the side
of contact. The€gap between the mandibular ramus and the atlas
Figure 5-61â•… End-play evaluation of the atlantooccipital articulation. A, Flexion. B, Extension.
�
transverse
process opens on the side opposite rotation and close on
the side of rotation. Occipital rotation is limited and occurs at the
end of �cervical rotation (Figure 5-62).
C0–1 Lateral Flexion.╇ Lateral flexion is evaluated by placing
the index finger between the inferior tip of the mastoid process
and the atlas transverse process (Figure 5-63). This interspace is
difficult to locate because of its small size and the overlying musculature. The head is laterally flexed away from the side of contact, and the gap between the mastoid and atlas transverse should
open on the side opposite the lateral flexion. End play is evaluated on the side of lateral flexion for medial glide. To evaluate
medial glide, the doctor contacts the posterior lateral aspect of
the occiput with the lateral surface of the index finger (or fingertips of the index and middle fingers). The patient’s head is
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167
Figure 5-63â•… Palpation of left lateral flexion at the atlanto-occipital
articulation.
Figure 5-65â•… Palpation of left rotation at the
5-65
atlantoaxial joint and anterior-to-posterior glide of
the right C1 articular pillar.
Figure 5-64â•… Palpation of right lateral flexion
5-64
end play of the atlanto-occipital articulation. The
doctor’s right hand applies medial pressure while the left hand distracts
superiorly.
�
laterally
flexed toward the side of contact while the doctor springs
medially at the end ROM (Figure 5-64).
Segmental Range of Motion and End Play (C1–2). C1–2
Rotation (Posterior-to-Anterior Glide). To evaluate atlantoaxial rotation, contact the posterior lateral aspect of the transverse process
of the atlas and axis overlapping the C1–2 intertransverse space with
the palmar surfaces of the middle and index fingers. The contacts
are established on the side opposite cervical rotation, and the head is
laterally flexed a few degrees toward the contact and passively rotated
away from the side of contact (Figure 5-65). The doctor should palpate anterior rotation of C1 and Â�separation of the C1–2 intertransverse space on the side opposite rotation (side of contact). At the
end of passive rotation, evaluate end play by applying forward overpressure against the transverse process of C1. The atlantoaxial articulation lacks a strong interlaminar �ligament and has a loose joint
capsule, allowing for a comparatively flexible end play.
C1–2 Medial Glide. Establish an index contact on the lateral
surface of the atlas transverse process. The patient’s head is laterally
flexed toward the side of contact while medial springing �pressure
5-66
Figure 5-66â•… Palpation of right-to-left medial
glide of C1.
is applied against the atlas transverse process (Figure 5-66). Lateral
flexion at the atlas is limited; this procedure is designed to assess
the small degree of medial glide that should be present, not the
active range of lateral flexion.
C1–2 Flexion and Extension. Establish bilateral contacts over the
C1–2 articulation. The structures are deep and difficult to directly
palpate. They are identified by a sense of fullness through the soft
tissues. Use the index and middle fingers on one side and a thumb
contact on the other. The patient’s head is flexed and extended at
the C1–2 articulation. Palpate for posteroinferior (PI) glide of the
atlas during extension and AS glide during flexion (Figure 5-67). At
the end of passive motion, evaluate end play by springing anterosuperiorly for flexion and anteroinferiorly for€extension. The end
play is elastic but firm compared with �rotation end play.
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| Chiropractic Technique
A
Figure 5-67â•… Palpation of flexion at the atlantoaxial articulation.
Segmental Range of Motion and End Play (C2–C7). The
lower cervical spine may be evaluated with the patient in the sitting or supine position. In the sitting position, the doctor �controls
movement by contacting the patient’s forehead or the crown of
the patient’s head. In the supine position, passive movement is
controlled by cupping the patient’s contralateral occiput and
mastoid.
Rotation (Posterior-to-Anterior Glide). Evaluate movement by
placing the palmar surface of the index or index and middle fingers over the articular pillars. With the patient in the sitting position, use either an upright (palm up) or reverse (palm down) hand
contact method (Figure 5-68). Establish palpation contacts on the
posterior surface of the articular pillars on the side �opposite �cervical
rotation. The patient’s head is passively rotated away from the side
of contact. The superior pillar should move forward relative to those
below, and the soft tissues should elongate under the contact. With
full rotation you should note a stair-stepping effect from the lower
to upper cervical spine. At the end of passive motion, evaluate end
play by springing from the posterior to the anterior, along the facet
planes, normally encountering firm and elastic but giving end play.
Rotation (Anterior-to-Posterior Glide). When evaluating this
motion with the patient in the sitting position, stand behind the
patient, opposite the side of contact. Establish a soft contact with
the ventral surface of the index and middle fingers over the anterolateral (AL) surface of the articular pillars. Take care to avoid
excessive pressure over the anterior neurovascular structures.
The stabilization hand contacts the patient’s forehead or the top
of the patient’s head. The patient’s head is laterally flexed away
and rotated toward the side of contact to induce A-P gliding and
�gapping of the articulations under the area of contact. In addition
B
C
Figure 5-68╅ Palpation of rotation and �posterior5-68C
to-anterior glide at the C3–4 articulation. A, Right
rotation with the palm down. B, Left rotation with the palm up. C,
Left rotation in the supine position.
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169
Figure 5-69â•… Palpation of right rotation and
5-69
anterior-to-posterior glide at the right C2–3 articulation in the seated position.
5-71
Figure 5-70â•… Palpation of right rotation and
5-70
�
anterior-to-posterior glide at the right C2–3 articulation in the supine position. Doctor’s right thumb establishes the palpation
contact over the right C2–3 articulation.
to the A-P palpation vector (VEC), a slight inferior-to-superior
(I-S) orientation should be maintained so that the palpation VEC
is at a 90-degree angle to the facet plane (Figure 5-69). Evaluate
end-play motion by springing from the anterior to the posterior
along the same palpation VEC. You may also perform this method
with the patient in the supine position by establishing a soft anterior lateral pillar contact with the thumb of your hand corresponding to the side of palpation (Figure 5-70).
C2–C7 Lateral Flexion. To assess lateral flexion, establish segmental contacts over the articular pillars slightly posterior to the
midcoronal plane. If the contacts are placed too far anteriorly, they
Figure 5-71â•… Palpation of right lateral flexion of
the C5-6 joint.
can become uncomfortable to the patient. Segmental contacts may
be established unilateral or bilaterally. They may be established with
the index and middle fingers of one or both hands or with the fingers and thumb of the same hand. When using unilateral fingertip
contacts, stand to the side opposite the contact and change palpation hands and sides as you evaluate movement to each side (Figure
5-71). With the patient in the supine position, kneel at the head of
the table and use bilateral fingertip or index contacts (Figure 5-72).
During the assessment of lateral flexion, palpate bending of
the articular pillar on the side of lateral flexion and elongation of
the soft tissues on the side opposite the lateral flexion (see Figure
5-71). At the end of passive motion, evaluate end play by applying
additional overpressure by pushing toward the midline from the
side of lateral flexion (concave toward convex). The VEC should
incorporate an inferior inclination to avoid compressing the soft
tissues. The end-play quality for lateral flexion is similar to that of
rotation—firm but giving and elastic.
C2–C7 Flexion and Extension. To evaluate segmental flexion
and extension, establish bilateral or unilateral contacts over the
posterior articular pillars. Establish the segmental contacts with
the fingertips or with the fingertips and thumb of the same hand
(Figure 5-73). During extension, palpate PI gliding of the articular pillars. During flexion, palpate AS gliding of the articular pillars. Evaluate flexion end play by applying additional overpressure
in an AS direction, and evaluate extension by applying additional
overpressure through the palpation hand in an anterior direction.
Extension movement is perceived as anterior glide and an increase
in the cervical lordosis and flexion as posterior movement and
reversal of cervical lordosis. The quality of end play for flexion is
more resistant as a result of strong posterior neck muscles.
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B
A
5-72B
Figure 5-72â•… Palpation of right lateral flexion of C5–C6 in the supine position with a fingertip contact (A) and an index contact
(B) of the right C5–C6 articulation.
Overview of Cervical Spine Adjustments
The cervical spine is flexible and composed of small structures.
It is easy to overpower the neck, so caution must be used in the
delivery of cervical adjustments. Adjustments of the cervical spine
are performed with the patient in sitting, prone, and supine positions. Most techniques involve adjustive positions that produce
movement of head and motion segments in the direction of joint
A
5-73B
restriction and adjustment. Therefore the majority of the adjustments presented (assisted methods) are applied to develop tension
in the motion segments inferior to the level of segmental contact.
Resisted methods are used less frequently. When resisted methods
are applied, they are typically used in the treatment of rotational
dysfunction. Resisted cervical or thoracocervical adjustments
are€applied to develop maximal tension in the motion segments
superior to the level of established contact.
B
Figure 5-73â•… Palpation of cervical flexion at the C3–4 motion segment in the supine position (A) and the seated position (B).
(Continuedâ•›)
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171
C
5-73C
Figure 5-73—Cont’dâ•… C, Palpation of Â�cervical
extension at the C3–4 articulation.
Rotational Dysfunction
Rotational dysfunction of the cervical spine has been postulated to
result from loss of anterior glide of the facets on the side opposite the
direction of rotation restriction (side of posterior body rotation) or
posterior movement and gapping on the side of rotational restriction
(Figure 5-74). The side and site of fixation is assessed by determining
the side of subjective and palpable discomfort and comparing the endplay quality of P-A glide on one side to the A-P glide on the other.
Dysfunction may be treated with assisted methods by contacting the posterior pillar of the superior vertebra on the side of posterior body rotation (side opposite the rotation restriction). In the
lower cervical spine, the adjustive thrust would be directed anteriorly (Figure 5-75).
Figure 5-75â•… Index contact applied to the right
5-75
C3 articular pillar (dot), with adjustive force directed
anterosuperiorly (arrow) to induce left rotation of the right C3–4 motion
segment.
Methods directed at inducing posterior glide and gapping on
the side of restricted rotation may be treated with either assisted or
resisted methods. In both techniques, the cervical spine is laterally
flexed away from the side of contact to lock the contralateral joints
and distract the joint to be adjusted. With assisted methods, the
contacts are established on the ipsilateral-anterolateral pillar of the
�superior vertebra on the side of rotational restriction (side opposite
the posterior body rotation). The adjustive thrust is directed in a posterior direction (Figure 5-76). When resisted methods are applied,
the contacts are established on the spinous process of the inferior
vertebra on the side opposite the rotation restriction (inferior vertebra on the side of posterior body rotation). The adjustive thrust is
directed medially through the spinous contact, resisted by the counter-rotational positioning of the patient’s head (Figure 5-77).
Lateral Flexion Dysfunction
Figure 5-74â•… Posterior view of the cervical spine, illustrating left rotation characterized by anterosuperior glide of the right facet joints and
posteroinferior glide of the left facet joints.
Lateral flexion dysfunction of the cervical spine may result from a
loss of inferior glide and approximation of the joints on the side of
lateral flexion dysfunction or a loss of contralateral superior glide
on the side opposite lateral flexion restriction (Figure 5-78). The
exception is the atlantoaxial articulation, which has horizontal
facet planes and very limited lateral flexion. Determination of sites
and direction of restriction are assessed by end feel evaluation.
Lateral flexion dysfunction is typically treated with assisted
methods. In the lower cervical spine, lateral flexion is induced
by contacting the articular pillar of the superior vertebrae on the
side of lateral flexion restriction and applying adjustive thrusts
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| Chiropractic Technique
5-76
5-77
Figure 5-76â•… Assisted method. Thumb contact established over the right anterolateral pillar of C4, with adjustive force directed
posteriorly (arrow) to induce right rotation and gapping in the right C4–5 articulation.
Figure 5-77â•… Resisted method. Index contact established on the left spinous process of C4, with adjustive force directed medially to induce right rotation and gapping in the right C4–5 articulation.
medially and inferiorly along the facet planes (Figure 5-79, A).
Techniques directed at inducing unilateral long-axis distraction
of the posterior joints may also be applied to treat restrictions
in lateral flexion by inducing distraction in the affected joints
(Figure 5-79, B).
Lateral flexion restrictions in the atlanto-occipital (C0–C1)
joint are distinctive because of the unique anatomy. Methods
applied to induce lateral flexion movement in C0–C1 can be
applied with contacts established on the ipsilateral or contralateral
side of lateral flexion restriction (Figure 5-80, A–C).
Flexion and Extension Dysfunction
Figure 5-78â•… Posterior view of the cervical spine, illustrating left lateral flexion and superior glide of the right facet joints and inferior glide
of the left facet joints.
Flexion restrictions (extension malpositions) may be treated
with methods that induce gliding distraction in the facet
joints. Many of the methods described for treating lateral flexion restrictions and rotational restrictions induce movements
that may effectively induce this movement. Adjustments
that induce long-axis distraction may also alleviate restrictions in flexion by inducing joint distraction (see Figure
5-79, B). Prone methods are also described for cervical flexion
A
B
Figure 5-79â•… A Index contact applied to the left posterolateral articular pillar of C3, with adjustive force directed
5-79A
medioinferiorly (arrow) to induce left lateral flexion of the C3–4 motion segment. B, Adjustment applied to induce long-axis
Â�distraction in the left C2–3 articulation.
A
B
C
D
Figure 5-80â•… A, Hypothenar contact applied to the left inferior aspect of the occiput to distract the left atlanto-occipital articulation.
5-80A
B, Thumb contact applied to the left inferior aspect of the occiput to distract the left atlantooccipital articulation. C, Hypothenar contact applied to the left lateral aspect of the occiput to induce left lateral flexion of C0–C1. D, Hypothenar contact applied to the right inferior aspect of the
occiput to extend the C0–C1 articulation.
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| Chiropractic Technique
A
B
Figure 5-81â•… A, Adjustment applied to midcervical spine to induce flexion with a posterior-to-anterior (P-A) and inferior-to-superior (I-S) vector.
B, Adjustment applied to midcervical spine to induce extension with P-A vector.
�restrictions (Figure 5-81, A) but it is questionable whether segmental flexion can be induced with a prone stationary position
and a posterior to anterior thrust.
Cervical extension induces motion that stretches the capsule
and its periarticular tissue in directions not specifically addressed
with rotation or lateral flexion adjustments. Therefore, extension
restrictions (flexion malpositions) are more effectively addressed
by adjustive techniques and VECs directed specifically for this
dysfunction. When applying prone methods establish contacts
in the midline over the spinous process or both articular pillars
(see Figure 5-81, B), prestress the joint into extension and deliver
a thrust anteriorly. When applying extension adjustments, use
extreme caution to avoid excessive extension and joint compression. The thrust must be shallow and gentle.
Atlanto-occipital restrictions in flexion (extension malposition) are treated with methods directed at inducing posterosuperior glide or long-axis distraction of the occipital condyle
(Figure 5-80, A and B). Restrictions in extension (flexion
malposition) are treated with methods directed at inducing
anteroinferior glide of the occipital condyle (Figure 5-80, D).
The thrust is directed mainly in the sagittal plane, with limited cervical rotation and some segmental lateral flexion to
isolate the joint.
All adjustive techniques described in Chapters 5 and 6 are
structured around the abbreviations and symbols presented in
Box 5-3. The adjustive techniques in this chapter have been given
names that are based on the involved joint or region, patient
position, contact used by the clinician, body part contacted,
and any necessary additional information (e.g., push, pull, with
distraction, etc.), as well as the induced joint movement. These
BOX 5-3
bbreviations Used in Illustrating
A
Technique
The following abbreviations are used
throughout the chapter:
INDâ•… Indications
PPâ•… Patient positioning
DPâ•… Doctor positioning
SCPâ•… Segmental contact point on patient
CPâ•… Contact point
IHâ•… Indifferent hand
VECâ•… Vector
Pâ•… Procedure
→ Arrows on photographs indicate direction of force.
ΔTriangles on photographs indicate stabilization.
names follow the patterns used by the U.S. National Board of
Chiropractic Examiners and are designed to be helpful in the
teaching and testing for competence of the procedures (see Boxes
5-4–5-10).
Upper Cervical Spine Adjustments (Box 5-4)
Supine
Hypothenar/Occiput Lift (Figure 5-82)
IND: Restricted flexion, C0-1. Extension malposition, C0-1. Loss
of long-axis distraction, C0-1.
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BOX 5-4
175
Upper Cervical Adjustments
• Supine
• Hypothenar/occiput lift (Figure 5-82)
• Hypothenar/occiput push (Figure 5-83)
• Calcaneal/zygomatic push (Figure 5-84)
• Index/atlas push (Figure 5-85)
• Sitting
• Calcaneal/zygomatic pull (Figure 5-86)
• Index/occiput lift (Figure 5-87)
• Index/occiput push (Figure 5-88)
• Index/atlas push (Figures 5-89 and 5-90)
• Digit/atlas pull (Figure 5-91)
• Prone
• Thenar/occiput push: distraction (Figure 5-92)
• Thenar/occiput push: extension (Figure 5-93)
A
B
Figure 5-82â•… Hypothenar contact applied to the left inferior aspect of
the occiput to flex or distract the left atlanto-occipital articulation.
PP: The patient lies supine, with the doctor supporting the
patient’s head off of the end of the table and turned away from
the side of dysfunction.
DP: Stand at the head of the table, facing cephalad, on the side of
the adjustive contact in a low fencer stance, with weight shifted
toward the superior leg.
CP: Hypothenar of your caudal hand, with fingers pointing vertically
and resting on the skull. You may use an optional thumb contact.
SCP: Inferior edge of the occiput, medial to the mastoid.
IH: Your IH and fingers wrap around the patient’s chin while your
forearm supports the patient’s head.
VEC: I-S.
P: Establish the contacts and rotate the patient’s head away from
the side of adjustive contact. Apply preadjustive long-axis distraction by leaning your body weight headward. At tension,
deliver a shallow, vertically directed thrust superiorly through
the contact hand and body. Take care to minimize rotational
tension to the upper cervical spine.
Hypothenar/Occiput Push (Figure 5-83)
IND: Restricted rotation, lateral flexion, or extension, C0–1.
Rotation, lateral flexion, or flexion malpositions, C0–1.
PP: The patient lies supine with the head off of the end of the
table, supported by the doctor and turned away from the side
of dysfunction.
C
Figure 5-83â•… A, Hypothenar contact applied
5-83A, B
to the right inferior aspect of the occiput to extend
the C0–1 motion segment. B, Hypothenar contact applied to the left lateral aspect of the occiput to left laterally flex the C0–1 motion segment.
C, Hypothenar contact applied to the left posterolateral aspect of the
occiput to right rotate the left C0–1 motion segment.
DP: Stand at the head of the table on the side of the adjustive
�contact, angled 45 to 90 degrees to the patient.
CP: Hypothenar of the hand corresponding to the side of segmental contact (e.g., your right hand establishes the contact when
contacting the right occiput). The contact hand is arched to
cup over the patient’s ear, with fingers resting on the angle of
the jaw. Index or thenar contacts may be used as alternatives to
the hypothenar contact.
SCP: Occiput (posterior supramastoid groove), just posterior to
the ear.
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IH: Your IH supports and cradles the patient’s head, with fingers
running along the base of the occiput.
VEC: P-A, S-I, and L-M to induce extension. L-M and S-I to
induce lateral flexion.
P: Establish the contacts and laterally flex the head toward the
side of contact while rotating it away. The degree of associated occipital extension or lateral flexion depends on the
dysfunction being treated. After you establish joint tension,
generate a thrust your shoulder along the desired VEC. Take
care to minimize full rotational tension to the upper �cervical
spine.
Extension, C0–1 (see Figure 5-83, A): When inducing extension
or ipsilateral anterior glide, laterally flex the occiput toward the
side of contact and prestress into extension.
Lateral flexion, C0–1 (Figure 5-83, B): When inducing lateral
flexion, limit extension of the occiput and induce lateral flexion toward the side of adjustive contact.
Rotation, C0–1 (Figure 5-83, C): When inducing occipital
rotation or ipsilateral anterior glide, rotate the patient’s
head away from the side of adjustive contact. Avoid full
rotational tension when treating rotational restrictions in
the upper cervical spine. Rotational movement between the
occiput and the atlas is very limited, and it is not necessary
to develop full cervical rotation to develop tension at the
C0-1 articulation. The incorporation of slight lateral flexion
toward the side of contact aids in developing earlier rotational tension.
Calcaneal/Zygomatic Push (Figure 5-84)
IND: Lateral flexion restrictions and malpositions, C0–1.
PP: The patient lies supine, with the head rotated away from the
side of contact and lateral flexion restriction.
DP: Stand at the side of the table behind the patient’s head in a
square stance.
CP: Calcaneal contact (heel of the hand) of the caudal hand, with
the fingers pointing toward the vertex of the skull.
SCP: Zygomatic arch.
IH: Your cephalad hand cups the down-side ear with the palm
while your fingers wrap around the occiput and upper cervical vertebra.
VEC: L-M.
P: Apply L-M pressure against the zygomatic arch as your IH
exerts superior traction against the down-side occiput. At tension, deliver an impulse thrust through both arms, creating a
scooping action and L-M movement. Take care to minimize
full rotational tension to the upper cervical spine.
Index/Atlas Push (Figure 5-85)
IND: Rotation, lateral flexion restrictions/malpositions, C1–2.
Extension restriction (flexion malposition), C1–2.
PP: The patient lies supine.
DP: Stand at the head of table on the side of the adjustive contact,
angled 45 to 90 degrees to the patient.
CP: Proximal ventrolateral surface of the index finger of your hand
corresponding to the side of segmental contact. Your thumb
rests on the patient’s cheek while the remaining fingers support
the contact and cup the base of the occiput.
SCP: Lateral aspect of the transverse process of the atlas for inducing lateral flexion. Posterior aspect of the transverse process for
inducing rotation or coupled extension.
IH: Your IH cradles the patient’s head and supports the contralateral occiput.
VEC: P-A, with clockwise or counterclockwise rotation to induce
rotation. P-A to induce ipsilateral extension. Medial-to-lateral
(M-L) to induce lateral flexion.
P: Rotate the patient’s head away from the side of dysfunction
and establish the contact. The degree of additional rotation,
extension, or lateral flexion depends on the dysfunction being
treated. After joint tension is established, generate an impulse
thrust along the desired VEC.
Rotation (Figure 5-85, A): When treating rotational dysfunction, rotate the patient’s head away from and slightly laterally
flex the patient’s head toward the side of adjustive contact.
At tension, deliver a rotational impulse thrust through your
wrist and forearms. Avoid full rotational tension with extension when treating rotation restrictions in the upper cervical
spine. Rotational tension may be achieved earlier in the arc
of motion by inducing slight lateral flexion toward the side
of contact.
Lateral flexion (Figure 5-85, B): When treating restrictions in lateral flexion, contact the lateral surface of the atlas transverse,
minimize rotation of the cervical spine, and thrust laterally to
medially.
Extension (Figure 5-85, C): When treating coupled extension
restrictions, minimize the rotation of the cervical spine while
prestressing the joint into extension. Establish contact over the
posterolateral mass and deliver a thrust anteriorly by inducing
shoulder flexion.
Sitting
Figure 5-84â•… Hypothenar (calcaneal) contact applied over the right
zygomatic arch to right laterally flex the atlanto-occipital motion segment.
Calcaneal/Zygomatic Pull (Figure 5-86)
IND: Restricted flexion, C0–1. Extension misalignment, C0–1.
PP: The patient is seated.
DP: Stand behind the patient with a rolled towel or foam block
between your torso and the patient’s cervical spine. This is
intended to maintain the cervical curve and support the cervical segments during the thrust.
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A
177
Figure 5-86â•… Bilateral calcaneal zygoma contacts applied to the
Â�zygomatic arches to induce flexion in the C0–1 motion segment.
CP: Calcaneal contact of both hands, with the fingers pointing
cephalic (arching over the patient’s eyes). Alternatively, reinforced pisiform contacts can be established over the glabellar
region.
SCP: Superior aspect of the zygoma bilaterally.
IH: Same as the contact hand.
VEC: S-I.
P: Establish the contacts by compressing the patient’s head against
your body and applying long-axis distraction through the legs.
Apply preadjustive tension in flexion, and then deliver an A–P
and S–I thrust equally through both hands.
B
Index/Occipital Lift (Figure 5-87)
IND: Restricted flexion, lateral flexion, or loss of long-axis distraction, C0-1. Extension or lateral flexion malpositions, C0-1.
PP: The patient sits in a cervical chair, with the head turned
away from the side of contact and resting against your chest.
DP: Stand behind the patient, slightly toward the side of cervical
rotation.
CP: Proximal palmar surface of the middle finger of the hand corresponding to the side of head rotation (e.g., your left hand
C
Figure 5-85â•… A, Index contact applied to the left
5-85A,
B
atlas transverse process to right rotate the C1–2
motion segment. B, Index contact applied to the left atlas transverse
process to left laterally flex the C1–2 motion segment. C, Index contact
applied to the posterior aspect of the left atlas transverse process to extend
the left C1–2 motion segment.
Figure 5-87â•… Middle finger contact applied to the
5-87
right lateral and inferior aspect of the occiput to distract the right atlanto-occipital articulation.
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| Chiropractic Technique
establishes the contact on the right occiput when the patient’s
head is rotated to the left).
SCP: Inferior border of occiput and lateral border of the mastoid
process on the side of dysfunction.
IH: Reinforces the contact hand and stabilizes the patient’s head
against your chest.
VEC: I-S for flexion or long-axis distraction. L-M and I-S for lateral flexion dysfunction.
P: Place the patient in the sitting position and rotate the patient’s head
away from the side of contact. Reach around the patient’s face to
contact the dysfunctional joint (a pillow may be used to cushion
the patient’s head against your chest). Develop Â�preadjustive joint
tension by tractioning vertically with arms and legs.
Long-axis distraction: To induce long-axis distraction or occipital flexion, thrust headward with a lifting impulse generated
through the arms and legs.
Lateral flexion: To induce lateral flexion, accentuate bending of
the patient’s head away from you and thrust laterally to medially through the contact arms while maintaining long-axis distraction. Take care to minimize full rotational tension to the
upper cervical spine.
Index/Occiput Push (Figure 5-88)
IND: Restricted rotation, lateral flexion, or extension, C0–C1.
Rotation, lateral flexion, or flexion malpositions, C0–C1.
PP: The patient sits relaxed in a cervical chair.
DP: Stand behind the patient, toward the side of segmental contact.
CP: Ventrolateral surface of the index finger of the hand corresponding to the side of segmental contact. The palm is turned€up, with
wrist straight. The forearm is approximately 45 degrees to the
patient, with the remaining fingers cupping the lower occiput.
SCP: Occiput, supramastoid groove on the side of the lesion.
IH: Cups the patient’s head and supports the contralateral occiput.
VEC: P-A, S-I, and L-M to induce extension. L-M, S-I, and P-A
to induce lateral flexion.
Figure 5-88â•… Index contact applied to the right
5-88
posterior and inferior aspect of the occiput to extend
the atlanto-occipital motion segment.
P: Establish stabilization and segmental contact points (SCPs),
keeping contact arm angled approximately 45 degrees to the
patient’s shoulders. Laterally flex the patient’s head toward the
side of contact, with slight rotation of the head away. The degree
of comparative extension and lateral flexion depends on the
direction of C0–1 restricted movement. When inducing extension direct the adjustive VEC more anteriorly, and when inducing lateral flexion direct the thrust more medially. Take care to
minimize rotational tension to the upper cervical spine.
Index/Atlas Push (Figures 5-89 and 5-90)
IND: Restricted rotation, lateral flexion, or extension, C1–2.
Rotation, lateral flexion, or flexion malposition, C1–2.
PP: The patient sits relaxed in a cervical chair.
DP: Stand behind the patient, toward the side of segmental contact.
CP: Proximal ventral surface of the index finger of the hand corresponding to the side of segmental contact. The palm is turned
up, with the wrist straight. The forearm is approximately
90€degrees to the patient, with the remaining fingers cupping
the lower occiput.
SCP: Atlas transverse process: Lateral aspect for inducing lateral
flexion. Posterior aspect for inducing rotation and extension.
IH: Cradles the patient’s head by cupping the patient’s ear and
inferior occipital rim.
VEC: P-A, with clockwise or counterclockwise rotation to induce
rotation. P-A to induce extension. M-L to induce lateral flexion.
P: Rotate the patient’s head away from the side of dysfunction
and establish the contacts. The degree of additional rotation,
extension, or lateral flexion depends on the dysfunction being
treated. After joint tension is established, generate a thrust
with your shoulder along the desired VEC.
Figure 5-89╅ Index contact applied to the �posterior
5-89
aspect of the right transverse process of the atlas to
induce left rotation at C1–2.
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5-90
Figure 5-90â•… Index contact applied to the left
atlas transverse process to left laterally flex C1–2.
Rotation (see Figure 5-89): When treating rotational dysfunction,
rotate the patient’s head away from and flex it slightly laterally toward the side of adjustive contact. At tension, deliver
a rotational impulse thrust through the wrist and forearms.
Minimize full rotational tension with extension by inducing
slight lateral flexion toward the side of contact.
Lateral flexion (see Figure 5-90): When treating lateral flexion
dysfunction, minimize rotation of the cervical spine and thrust
laterally to medially by adducting your shoulder.
Extension: When inducing extension minimize rotation of the
cervical spine while prestressing the joint into extension.
Establish the contact over the posterior lateral mass and thrust
anteriorly by inducing shoulder flexion.
Digit/Atlas Pull (Figure 5-91)
IND: Restricted rotation, C1–2. Rotational malposition, C1–2.
PP: The patient sits relaxed in a cervical chair.
DP: Stand, facing the patient on the side opposite the segmental
contact.
CP: Palmar surface of the middle finger of the hand corresponding to the side of segmental contact. The thenar of the contact
hand rests on the cheek of the patient.
SCP: Posterior aspect of atlas transverse.
IH: With fingers running vertically, stabilizes the patient’s
head by supporting the contralateral occiput and temporal
region.
VEC: P-A, with clockwise or counterclockwise rotation.
P: Rotate the patient’s head away from and slightly laterally flex it
toward the side of adjustive contact. Induce rotation and ipsilateral anterior glide by developing a pulling impulse thrust
through the contact hand by quickly extending the shoulder.
(The same principles for minimizing extension and rotational
tension in the upper cervical spine apply here also.)
179
Figure 5-91â•… Middle finger contact applied to
5-91
the posterior aspect of the left atlas transverse process to induce right rotation at C1–2.
Prone
Thenar/Occiput Push: Distraction (Figure 5-92)
IND: Restricted flexion, C0-1. Loss of long-axis distraction, C0–1.
Extension malposition, C0–1.
PP: The patient lies prone, with the head placed in slight flexion.
DP: Stand on either side of the patient in a fencer stance, caudal
to the contact, facing cephalad.
CP: Thenar eminence of both hands.
SCP: Establish the contacts bilaterally on the inferior aspect of the
occiput, medial to the mastoid.
VEC: I-S, P-A.
Figure 5-92â•… Bilateral thenar contacts applied to the posteroinferior
aspect of the occiput to flex the atlanto-occipital motion segment.
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| Chiropractic Technique
P: Center your body over the patient in low fencer position, caudal
to the contacts, and traction headward. Tension may be developed through both contacts or centered to one side. After joint
tension is reached, deliver a cephalically directed thrust through
your arms and trunk. The impulse may be directed at one or
both articulations. This adjustment may be performed on a
drop table or performed as a mobilization procedure.
Thenar/Occiput Push: Extension (Figure 5-93)
IND: Restricted extension, flexion malposition, C0–1.
PP: The patient lies prone, with the head placed in slight extension.
DP: Stand on either side of the patient in a fencer stance, facing
cephalically, centered over the contacts.
CP: Thenar eminence of both hands.
SCP: Establish the contacts bilaterally on the posterior occiput, at
or above the level of the superior nuchal line.
VEC: P-A
P: Center your body over the patient and deliver an impulse thrust
anteriorly. Tension may be developed through both contacts or
centered to one side. This adjustment may be performed on a
drop table or performed as a mobilization procedure.
Lower Cervical Spine Adjustments
(Box 5-5)
BOX 5-5
Lower Cervical Adjustments
• Supine
• Index/pillar push (Figure 5-94)
• Index/spinous push (Figure 5-95)
• Thumb/pillar push (Figure 5-96)
• Thumb/pillar pull (Figure 5-97)
• Digit/pillar pull (Figure 5-98)
• Hypothenar/pillar push (Figure 5-99)
• Sitting
• Digit/pillar pull (Figure 5-100)
• Index/pillar push (Figure 5-101)
• Index/spinous push (Figure 5-102)
• Hypothenar/pillar push (Figure 5-103)
• Prone
• Index/pillar/push (Figure 5-104)
• Hypothenar/spinous push (Figure 5-105)
• Bilateral index/pillar push (Figure 5-106)
Supine
Index/Pillar Push (Figure 5-94)
IND: Restricted rotation, lateral flexion, or extension, C2–C7.
Rotation, lateral flexion, or flexion malpositions, C2–C7.
PP: The patient lies supine.
DP: Stand at the head of the table on the side of the adjustive
�contact, angled 45 to 90 degrees to the patient.
CP: Ventrolateral surface of the index finger of the hand corresponding to the side of segmental contact. The thumb or thenar rests on
the patient’s cheek as the remaining fingers reinforce the Â�contact.
Figure 5-93â•… Bilateral thenar contacts applied to the posterior aspect
of the occiput to extend the atlanto-occipital motion segment.
Use the proximal surface of the index finger in upper cervical segments and the distal surface in the lower cervical segments.
SCP: Posterior articular pillar of superior vertebrae.
IH: Cradles the patient’s head and supports the contralateral
occiput and upper cervical spine.
VEC: P-A with clockwise or counterclockwise rotation to induce
rotation M-L and S-I to induce lateral flexion.
P: Rotate the patient’s head away from the side of dysfunction and
establish the adjustive contact. The degree of �additional �rotation,
extension, or lateral flexion depends on the �dysfunction being
treated.
Rotation (Figure 5-94, A): Establish the adjustive contact on the
superior articular pillar, rotate the patient’s head away while laterally flexing it toward the side of contact. Lateral flexion is incorporated in the positioning of this adjustment to induce unphysiologic
movement and approximate the joints above the contact. The
degree of lateral flexion should not be excessive or it may lead to
compression and locking of the joints to be distracted. At tension,
deliver the thrust through the wrists and forearms in a clockwise or
counterclockwise direction along the planes of the facet joint.
Lateral flexion (Figure 5-94, B): To induce lateral flexion, laterally flex the head toward the side of contact while minimizing
rotation, thrust medioinferiorly.
Extension: To induce segmental extension, prestress the involved joint
into extension, contact the posterior pillar, and thrust anteriorly.
Index/Spinous Push (Figure 5-95)
IND: Restricted rotation or lateral flexion, C2–T3. Rotation or
lateral flexion malpositions, C2–T3.
PP: The patient lies supine.
DP: Stand at the head of table on the side of the adjustive contact,
angled 45 to 90 degrees to the patient.
CP: Ventrolateral surface of the index finger of the hand corresponding to the side of segmental contact, with the remaining
fingers reinforcing the contact.
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181
B
A
5-94A, B
Figure 5-94â•… A, Index contact applied to the posterior aspect of the right C2 articular pillar to induce left rotation of C2–3.
B,€Index Â�contact applied to the lateral aspect of the C3 articular pillar to left laterally flex C3–4.
B
A
C
Figure 5-95â•… A, Index contact applied to the lateral aspect of the C6 spinous process to left rotate. B, Index contact applied to
5-95C
the left lateral aspect of the C6 spinous process to left rotate and/or to left laterally flex the C6–7 motion segment. C, Resisted
method. Index contact applied to the left lateral
�
aspect of the C6 spinous process to right rotate the C6–7 motion segment.
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| Chiropractic Technique
SCP: Lateral surface of the spinous process (Figure 5-95, A).
IH: Cradles the patient’s head and supports the contralateral
occiput and upper cervical spine. Support and control of the
patient’s head may be enhanced by placing the arm of your
contact hand against the patient’s forehead and gripping it
between the arm and forearm.
VEC: L-M and S-I
P: Rotate the patient’s head slightly away from you and establish
a contact on the lateral surface of the spinous process (Figure
5-95, A). The degree of additional rotation or lateral flexion
depends on the dysfunction being treated. After joint tension
is established, generate a thrust with your shoulder along the
desired VEC.
Rotation (Figure 5-95, B): To induce rotation with an assisted
contact (superior vertebra), use a more neutral patient position. Establish the contact on the superior spinous process on
the side of rotational restriction and rotate the patient’s head
away from the side of contact. The head should be rotated only
far enough to rest it in your IH. At tension, deliver a thrust
�primarily through the contact hand.
Rotational dysfunction may also be treated with resisted
methods. The resisted adjustive approach is designed to induce
�rotation and gapping in the facet joint contralateral and superior to the side of adjustive contact. When a resisted method is
used, the adjustive contact is established on the lateral surface
of the spinous process of the inferior vertebra on the side opposite the rotation restriction. Preadjustive tension is developed
by rotating the neck in the direction of restriction as counterpressure is applied against the spinous process. Lateral flexion is also induced toward the side of contact to distract the
contralateral facet joints and block the ipsilateral facet joints
(Figure 5-95, C). To deliver the impulse, counterthrust with
both hands. The contact hand thrusts medially by inducing
adduction of the shoulder. The IH induces counter-rotation by
supinating the forearm.
Lateral Flexion: Establish the adjustive contact over the �superior
vertebra on the side of lateral flexion restriction. Laterally flex
the patient’s head toward the side of adjustive contact and
deliver an impulse thrust medial, and anteroinferiorly through
the segmental contact.
Thumb/Pillar Push (Figure 5-96)
IND: Rotational restrictions and malpositions, C2–7.
PP: The patient lies supine.
DP: Stand at the head of the table on the side of the adjustive contact, angled approximately 90 degrees to the patient.
CP: Palmar surface of the thumb of the hand corresponding to
the side of segmental contact. The palm is turned down, with
fingers resting on the patient’s cheek.
SCP: PL pillar of the superior vertebra.
IH: Your IH cradles the patient’s head and supports the contralateral occiput and upper cervical spine.
VEC: P-A, with slight I-S inclination and clockwise or counterclockwise rotation.
P: After establishing contact, rotate the patient’s head away and
laterally flex it toward the side of contact. Lateral flexion is
incorporated in the positioning of this adjustment to induce
approximation of the joints above the contact level. The degree
of lateral flexion should not be excessive or it may lead to compression and locking of the joint to be distracted. The degree of
lateral flexion necessary to isolate the lower cervical segments
increases in a caudal direction. At tension, direct an impulse
thrust anteriorly by inducing rotation through your shoulder.
Thumb/Pillar Pull (Figure 5-97)
IND: Restricted rotation or combined restricted rotation and
opposite-side lateral flexion, C2–C7. Rotation and lateral flexion malpositions, C2–C7.
PP: The patient lies supine.
DP: Stand at the head of the table, opposite the side of the
adjustive contact, angled approximately 45 degrees to the
patient.
A
B
5-96
Figure 5-96â•… Thumb pillar posterior technique.
A, Thumb contact applied to the posterior aspect of
the right C3 articular �pillar. B, Procedure shown from the other side,
illustrating the treatment of a right rotation restriction at C3–4.
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183
B
A
C
Figure 5-97â•… Thumb pillar anterior technique. A, Thumb contact applied over the anterolateral aspect of the right C2
5-97B, C
�
articularpillar. B, Demonstration of procedure in the treatment of a right rotation restriction, applied to induce gapping in the right
C2–3 articulation. C,€Counterthrust technique, with contacts applied to the anterolateral aspect of the right C2 articular pillar and the left
lateral aspect of the C3 spinous process. Note support for contacts with the doctor’s shoulder.
CP: Palmar surface of the thumb of the hand corresponding to the
side of segmental contact. The palm is turned up, with the fingers and the palm of the contact hand supporting the occiput
and the upper cervical spine.
SCP: Anterolateral pillar of the superior vertebra (Figure 5-97, A).
IH: Your IH cups the ear, supporting the contralateral occiput
(Figure 5-97, B). Support of the patient’s head may be
improved by placing the arm of your contact hand against the
patient’s forehead and gripping it between the arm and forearm (Figure 5-97, C).
VEC: A-P, with slight I-S inclination, inducing clockwise or counterclockwise rotation.
P: After establishing the contacts, rotate the patient’s head toward and
laterally flex it away from the side of adjustive contact. At€tension,
direct an impulse thrust posteriorly by inducing adduction of your
shoulder and supination of the forearm. This adjustment is applied
to induce rotation and ipsilateral joint gapping at the articulation
below the contact level (Figure 5-97, B).
This adjustment may be combined with the index spinous
adjustment to induce a counter thrust (push/pull). In this
scenario, the IH contacts the spinous process of the lower
vertebrae on the contralateral side. At tension, both hands
thrust toward the �midline to induce counter-rotation
(Figure 5-97, C).
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| Chiropractic Technique
Figure 5-98â•… Index contact applied to the right articular pillar of C4
to induce left rotation in the C4–5 motion segment.
Digit/Pillar Pull (Figure 5-98)
IND: Rotational restriction and malpositions, C2–C7.
PP: The patient lies supine
DP: Stand at the head of the table, opposite the side of the adjustive contact
CP: Palmar surface of the middle finger of the hand corresponding to the side of segmental contact, with the palm resting on
the patient’s cheek.
SCP: Articular pillar of superior vertebrae.
IH: With fingers running horizontally, the IH stabilizes the
patient’s head by supporting the contralateral cheek, occiput,
and temporal region.
VEC: P-A, with slight I-S inclination and clockwise or counterclockwise rotation.
P: Rotate the patient’s head away from the side of contact and
laterally flex it slightly toward the side of contact. Rest the
patient’s head in the IH. At tension, direct a pulling impulse
thrust anteriorly along the facet planes by inducing shoulder
extension.
Hypothenar/Pillar Push (Figure 5-99)
IND: Restrictions in rotation, lateral flexion, or long-axis distraction, C2–C7. Malpositions in rotation and lateral flexion and
decreased interosseous spacing, C2–C7.
PP: The patient lies supine, head rotated, with side of contact up.
DP: Stand at the side of the table, behind the patient’s head.
CP: Pisiform-hypothenar contact of the caudad hand, with the
wrist in extension.
SCP: Articular pillar: posterior aspect for rotational dysfunction,
lateral aspect for long-axis dysfunction.
IH: The cephalad hand grasps the patient’s chin, allowing the
head to rest on your forearm.
VEC: P-A for rotation, I-S for long-axis distraction
P: The IH provides cephalad traction. At tension, deliver a cephalad thrust for a long-axis distraction and an anterior thrust to
induce rotation.
Sitting
Digit/Pillar Pull (Figure 5-100)
IND: Rotational restriction and malpositions, C2–C7.
PP: The patient sits relaxed in a cervical chair.
Figure 5-99â•… Hypothenar contact applied to the left lateral aspect of
the cervical articular pillars to induce long-axis distraction.
DP: Stand, facing the patient on the side opposite the segmental
contact.
CP: Palmar surface of the middle finger of the hand corresponding to the side of segmental contact, with the palm resting on
the patient’s cheek.
SCP: Articular pillar of the superior vertebra.
IH: With the fingers running vertically, the IH stabilizes the
patient’s head by supporting the contralateral occiput and
�temporal region.
VEC: P-A, with slight I-S inclination and clockwise or counterclockwise rotation.
P: Rotate the patient’s head away from the side of contact and
laterally flex it slightly toward the side of contact. At tension,
direct a pulling impulse thrust anteriorly along the facet planes
by inducing shoulder extension.
Index/Pillar Push (Figure 5-101)
IND: Restricted rotation, lateral flexion, or extension, C2–C7.
Rotation, lateral flexion, or flexion malpositions, C2–C7.
PP: The patient sits relaxed in a cervical chair.
DP: Stand behind the patient, toward the side of segmental
contact.
CP: Index finger of hand corresponding to the side of segmental contact. The palm is turned up, with the thumb and
thenar resting on the patient’s cheek. In the upper cervical
spine, establish the contact toward the proximal surface of the
index finger and toward the distal surface in the lower cervical spine.
SCP: Articular pillar of the superior vertebra.
IH: With fingers pointing down, the hand and fingers stabilize
the opposing occiput and cheek.
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185
A
5-100
Figure 5-100â•… Digital contact applied to the left C4
articular pillar to right rotate the C4–5 motion segment.
VEC: P-A, with clockwise or counterclockwise torque to induce
rotation (Figure 5-101, A), P-A to induce extension, and L-M
to induce lateral flexion (Figure 5-101, B).
P: Place the patient in a cervical chair, establish SCPs, and rotate
the patient’s head away from and slightly laterally flex it toward
the side of adjustive contact. To induce rotation, lateral flexion,
or extension, apply the same adjustive VECs presented for the
supine index pillar adjustment.
Index/Spinous Push (Figure 5-102)
IND: Restricted rotation or combined rotation and lateral flexion
restriction, C2–T3. Rotational or lateral flexion malpositions,
C2–T3.
PP: The patient sits relaxed in a cervical chair.
DP: Stand behind the patient, toward the side of segmental contact.
CP: Index finger of hand corresponding to the side of segmental
contact. The palm is turned up, with the thumb resting on the
patient’s cheek.
SCP: Lateral aspect of the spinous process.
IH: With fingers pointing down, the hand and fingers stabilize
the opposing occiput and cheek.
VEC: P-A and L-M.
P: Place the patient in a cervical chair, establish SCPs, and rotate
the patient’s head away from and slightly laterally flex it toward
the side of adjustive contact. At tension, an impulse thrust is
delivered anteriorly, medially, and inferiorly.
B
Figure 5-101â•… A, Index contact applied to the
5-101A,
B right articular pillar to left rotate the C3–4 motion
segment. B, Index contact applied to the right lateral aspect of the C3
articular pillar to right laterally flex the C3–4 motion segment.
Hypothenar/Pillar Push (Figure 5-103)
IND: Restricted rotation or combined restricted rotation and
opposite-side lateral flexion, C2–C7. Rotation and lateral flexion malpositions, C2–C7.
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| Chiropractic Technique
SCP: Anterolateral pillar of superior vertebra.
IH: With fingers running vertically, the IH stabilizes the contralateral upper cervical spine and occiput.
VEC: A-P and slightly I-S.
P: Stand in a fencer stance on the side of adjustive contact and
establish a broad, fleshy hypothenar contact over the anterolateral articular pillar. Rotate the patient’s head toward and
laterally flex it away from the side of adjustive contact. At
tension, direct an impulse thrust perpendicular to the facet
plane by thrusting posterosuperiorly through your shoulder.
Maintain slight vertical traction through both hands during
the delivery of the adjustment. This adjustment is applied
to induce A-P rotation and ipsilateral joint gapping at the
articulation below the �contact.
Prone
Figure 5-102â•… Index contact applied to the right lateral aspect of the C4
spinous process to right laterally flex or right rotate the C4–5 motion segment.
Figure 5-103â•… Hypothenar contact applied to
5-103
the anterolateral aspect of the right C4 articular pillar
to induce right rotation.
PP: The patient sits relaxed in a cervical chair.
DP: Stand in front of the patient, toward the side of contact.
CP: Hypothenar of hand corresponding to the side of adjustive
contact. The fingers of the contact hand extend obliquely vertically to provide stabilizing support to the patient’s head.
Index/Pillar Push (Figure 5-104)
IND: Restricted rotation or lateral flexion, C2–C7. Malpositions
in rotation or lateral flexion, C2–C7.
PP: The patient lies in the prone position, with the headrest
�lowered to induce slight thoracocervical flexion.
DP: Stand in a fencer stance on either side of table, facing
cephalad.
CP: Index finger (lateral aspect) of the hand corresponding to
the side of the adjustive contact. The wrist is held in ulnar
deviation, with the fingers pointing to the floor and the
thumb resting on the posterior cervical soft tissues (Figure
5-104, A).
SCP: Posterior aspect of the articular pillar of the superior vertebra (Figure 5-104, A).
IH: A thumb-web contact is established at the inferior rim of the
occiput while the palm and fingers contact the cheek and side
of the face.
VEC: P-A and slightly I-S for rotational restrictions. P-A and
superior-to-inferior (S-I) for lateral flexion restrictions.
P: The IH tractions the head cephalically while laterally flexing it
toward the contact and slightly rotating it away from the side
of adjustive contact (e.g., for left-sided contact, induce left lateral flexion and right rotation).
Rotation: To induce rotation, contact the posterior pillar on the
side opposite the rotational restriction and rotate the head in
the direction of joint restriction.
Lateral flexion: To induce lateral flexion, contact the articular pillar on the side of lateral flexion restriction and laterally flex
the neck toward the side of contact. At tension, thrust medioanteroinferiorly (Figure 5-104, B).
Hypothenar/Spinous Push (Figure 5-105)
IND: Flexion or extension restrictions or malpositions, C2–C7.
PP: The patient lies prone, with the patient’s neck flexed and headpiece slightly lowered for flexion restrictions (Figure 5-105)
and extended for extension restrictions.
DP: Stand in a fencer stance, facing cephalad.
SCP: Spinous process.
IH: The IH reinforces the contact hand with fingers pointing
vertically.
VEC: P-A.
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B
A
5-104
187
Figure 5-104â•… Index pillar prone technique. A, Index contact established over the posterior aspect of the left C5 articular
Â�process. B, Procedure shown to induce left lateral flexion and right rotate at the left C5–6 motion segment.
A
B
Figure 5-106â•… Bilateral index contacts established over the poste-
Figure 5-105â•… Hypothenar contact applied to the C6 spinous process
rior aspect of the C4 articular pillars to extend (A) or flex (B) the C4–5
motion segment.
to flex the C6–7 motion segment.
P: When treating flexion dysfunction, position the patient’s cervical spine into flexion and deliver a P-A and cephalically
directed impulse.
When treating extension dysfunction, position the patient’s
cervical spine in a slightly extended position and center your
body over the contact. Extension is induced by delivering an
impulse thrust anteriorly. When performing this adjustment,
use extra caution to avoid excessive depth and hyperextension
of the neck.
These adjustments can be performed on a drop table. A
drop mechanism that allows downward and forward movement may provide a mechanical advantage over a straight
downward drop by minimizing the compression and providing
axial distraction.
Bilateral Index/Pillar Push (Figure 5-106)
IND: Restricted extension C2–C7. Flexion malpositions, C2–C7.
PP: The patient lies prone.
DP: Stand in a fencer stance, facing cephalad, with the center of
gravity over the contact.
CP: Proximal index of both hands, with thumbs crossing at the
midline.
SCP: Posterior pillars.
VEC: P-A.
P: When treating flexion dysfunction, position the patient’s cervical spine into flexion and deliver a P-A and cephalically directed
impulse. It is unlikely that prone patient positions are the most
effective option for inducing cervical flexion.
When treating extension dysfunction, position the patient’s
cervical spine in a slightly extended position and center your
body over the contact. Extension is induced by delivering an
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| Chiropractic Technique
impulse thrust anteriorly. When performing this adjustment,
use extra caution to avoid excessive depth and hyperextension
of the neck.
These adjustments can be performed on a drop table. A drop
mechanism that allows downward and forward movement may
provide a mechanical advantage over a straight downward drop by
minimizing the compression and providing axial distraction.
THORACIC SPINE
In the thoracic spine, protection and function of the thoracic viscera take precedence over intersegmental spinal mobility. Although
the limiting anatomic structures make the thoracic spine the least
mobile part of the spinal column, the small movements that do
occur within the functional units are still significant. Although
more clinical attention has been focused around the cervical and
lumbar regions, the thoracic region is an area that must be considered important because of the possible mechanical changes that
may result in effects to the elements of the autonomic nervous
system. Furthermore, the addition of the articulations for the ribs
makes the thoracic region an exceptional structure. Finally, this
region seems to be prone to chronic postural problems affecting
sections of the thoracic spine and the supporting soft tissues (myofascial pain syndromes).
movement. The transverse processes arise from behind the superior articular processes. They are thick, strong, and relatively long,
with a concave facet on the anterior side. The intervertebral foramina in this region are essentially �circular in shape and fairly small
when compared with other areas of the spine (see Figure 5-107).
The articular facets form an angle of approximately 60 degrees
from the transverse toward the coronal plane and 20 degrees from
the coronal toward the sagittal plane (Figure 5-108). The inferior articular process arises from the laminae to face inferomedioanteriorly. The superior articular process arises from near the
�lamina-pedicle junction to face superolaterally and posteriorly.
The inferior articular process lies posterior to the superior articular process of the vertebra below.
The IVDs are comparatively shallow in the thoracic spine. The
disc height–to–body height ratio is 1:5, making it the smallest
ratio in the spine (Figure 5-109). This low ratio contributes to the
decreased flexibility of the thoracic spine. The nucleus is also more
centrally located within the annulus of the thoracic disc than it is
in either of the other two spinal regions.
Functional Anatomy
The body of the typical thoracic vertebra (T2–T8) is Â�heart-shaped,
with both the A-P and side-to-side dimensions of equal length
(Figure 5-107). The anterior surface of the body is convex from side
to side, and the posterior surface is deeply concave. Both the superior and inferior surfaces of the body are flat, with a ring around the
margin for attachment of the IVD. The pedicles of thoracic vertebrae are short and have inferior vertebral notches deeper and larger
than in any other part of the spine. The laminae are short, broad,
thick, and overlapping. The spinous processes are long and slender,
with a triangular shape in cross-section. They point obliquely downward, overlapping in the midthoracic spine and limiting extension
Transverse
process
Pedicle
Intervertebral
foramen
Transverse
ligament
20�
60�
A
B
Figure 5-108â•… The thoracic facet planes.
1:5
Vertebral
body
Radiate
ligament
Rib
Spinous
process
Figure 5-107â•… Typical thoracic motion segment.
4
3
3
10
Figure 5-109â•… The location of the nucleus and the disc height–to–
body height ratio in the thoracic spine.
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189
A
B
Figure 5-110â•… Structure of the atypical thoracic vertebra. A, T1
�vertebra. B, T12 vertebra.
One special feature of thoracic vertebrae is the presence of
costovertebral and costotransverse joints, which form the articulations for the ribs (see Figure 5-107). The costovertebral joints
(demifacets) are located on either side of the vertebral body to
form an articulation with the heads of the ribs. The costotransverse joints are located on the anterior aspects of the transverse
processes to articulate with the tubercles of the ribs.
The thoracic atypical vertebrae include T1 and T9 to T12
(Figure 5-110). The vertebral body of T1 resembles that of C7 and
possesses a whole facet for articulation with the first rib. The T9 vertebra may have no demifacets below, or it may have two demifacets
on either side (in which case, the T10 vertebra will have demifacets
only at the superior aspect). T10 has one full rib facet located partly
on the body of the vertebra and partly on the tubercle. The T11
segment has complete costal facets, but no facets on the transverse
processes for the rib tubercle. This vertebra also begins to take on
characteristics of a lumbar vertebra. The spinous process is short
and almost completely horizontal. T12 has complete facets on the
vertebra for articulation with the ribs, but otherwise resembles a
lumbar vertebra. The inferior articulating surfaces of T12 are convex and are directed laterally and anteriorly in the sagittal plane,
like those in the lumbar spine. Superior, inferior, and lateral tubercles (see Figure 5-110) replace the transverse processes.
45�
Figure 5-111â•… The location of the nucleus and the disc measurement
of the thoracic curve.
fracture, infection, endocrine abnormalities, trabecular deficiencies,
vitamin deficiencies, fluoride toxicity, and mechanical factors.23
Osteoporosis reduces the number and size of trabeculae in the
vertebral body, diminishing the axial loading stretch and resulting in
compression fractures, which accentuate the kyphotic curve. Dietary
deficiencies, malabsorption syndromes, steroid use, and endocrine
disorders have been implicated as causal factors of osteoporosis.24
Thoracic Curve
Range and Patterns of Motion
The thoracic spine forms a kyphotic curve of less than 55 degrees,18
with an accepted range of 20 to 50 degrees19,20 and an average of
45 degrees6 (Figure 5-111). It is a structural curve present from
birth and maintained by the wedge-shaped vertebral bodies that
are approximately 2 mm higher posteriorly. The thoracic curve
begins at T1–2 and extends down to T12, with the T6–7 disc
space as the apex.21
Alterations in the thoracic curve can be anatomic or postural.
A€change in the primary thoracic curve is likely to produce a change
in the secondary curves in the cervical and lumbar spine. The lumbar curve tends to increase, and the cervical curve decreases or shifts
forward, creating a cervical “poking” posture. This postural syndrome of forward head positioning and rounded and forward shoulders is often associated with chronic stretch weakness of the middle
and lower trapezius muscles. The chronic strain to the posterior
back and neck muscles can induce local myofascial pain syndromes
and headaches.22 As the thoracic kyphosis increases, it crowds the
�thoracic viscera, interfering with normal physiologic functioning.
Juvenile kyphosis (Scheuermann disease) and osteoporosis also
result in an increased thoracic kyphosis. In juvenile kyphosis the wedge
shape of the vertebral body is exaggerated, but the cause remains inconclusive. Theories of the pathogenesis include aseptic necrosis, endplate
Of the three cardinal planes of movement, sagittal plane movement of flexion and extension is the most restricted. Rotation and
lateral flexion demonstrate nearly equal movement, with each
exhibiting nearly twice as much movement as flexion and extension (Table 5-4; see Figure 5-24).
Movement in the upper thoracic spine is generally less than
in the lower. The exception is rotation, which decreases dramatically in the lower thoracic segments as the facet facings become
more sagittal.5 The instantaneous axis of movement for the thoracic spine, like other spinal regions, remains somewhat tentative.25 Using fresh cadaveric specimens, Panjabi and associates25
�determined the likely sites for flexion and extension, lateral flexion, and rotation (Figure 5-112).
Flexion and Extension
Combined flexion and extension in the thoracic spine averages
approximately 6 degrees per motion segment, demonstrating a
cephalocaudal increase in flexibility. Movement averages 4 degrees
in the upper thoracic spine, 6 degrees in the middle thoracic spine,
and 12 degrees in the lower two thoracic segments.5 Extension is
more limited than flexion because of the impaction of the articular
processes and spinous processes.
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| Chiropractic Technique
THORACIC
Flexion and
Extension
F
Lateral
Bending
E
R
Axial
Rotation
L
R
L
E
F
L
R
L�R
A
B
Figure 5-113â•… Extension (A) and flexion (B) of a thoracic segment.
Figure 5-112â•… Instantaneous axis of rotation for flexion and exten-
sion (A), lateral flexion (B), and axial rotation (C) in a thoracic segment.
(From White AA, Panjabi MM: Clinical biomechanics of the spine, ed 2,
Philadelphia, 1990, JB Lippincott.)
TABLE 5-4
Vertebra
T1–2
T2–3
T3–4
T4–5
T5–6
T6–7
T7–8
T8–9
T9–10
T10–11
T11–12
T12–L1
verage Range of Motion for the
A
Thoracic Spine
Combined
Flexion and
Extension
One-Side
Lateral
Flexion
One-Side
Axial
Rotation
4
4
4
4
4
5
6
6
6
9
12
12
5
6
5
6
6
6
6
6
6
7
9
8
9
8
8
8
8
7
7
9
4
2
2
2
Modified from White AA, Panjabi MM: Clinical biomechanics of the spine, ed 2, Philadelphia,
1990, JB Lippincott.
Thoracic flexion and extension combine sagittal plane rotation with slight sagittal plane translation. The degree of combined translation is minimal and uniform throughout the thoracic
spine.5 During flexion the articular facets glide apart as the IVD
opens posteriorly. During extension, the facet joints and posterior
disc approximate (Figure 5-113).
Lateral Flexion
Lateral flexion averages approximately 6 degrees to each side, with
the lower two segments averaging 7 to 9 degrees. Lateral flexion
is coupled with axial rotation throughout the thoracic spine. This
is especially apparent in the upper thoracic spine, where the pattern duplicates that of the cervical spine. The coupling is such
that lateral flexion and rotation occur to the same side (e.g., body
rotation to the concavity and spinous deviation to the convexity)5,26 (Figure 5-114). In the middle and lower thoracic spine,
the coupling is less distinct and may occur in either direction
(Figure 5-115).
Figure 5-114â•… Lateral flexion of an upper thoracic segment, showing
coupling movement in rotation and lateral flexion to the same side. This
pattern is the same as that of the cervical spine.
It is often assumed, however, that the lower thoracic segments
have a tendency to follow the coupling pattern of the lumbar spine.
The lumbar pattern is opposite that of the cervical and upper thoracic segments and incorporates lateral flexion with coupled axial
rotation in the opposite direction27,28 (see Figure 5-115). White and
Panjabi5 point out, however, that coupling patterns still remain controversial, and doctors must guard against any strong conclusions.
During lateral flexion, the IVD and facet joints approximate
on the side of lateral flexion and separate on the side opposite
lateral flexion (see Figure 5-114). In the upper thoracic spine the
inferior articular facets also glide medially relative to the superior
articular facet on the side of lateral flexion and laterally on the side
opposite lateral flexion. This is a result of the strong coupled axial
rotation in the upper thoracic spine.
Rotation
Segmental axial rotation averages 8 to 9 degrees in the upper thoracic spine (Figure 5-116). Rotational motion decreases slightly in
the middle thoracic spine and drops off dramatically to approximately 2 degrees in the lower two or three thoracic segments.5 The
marked decrease in rotational mobility in the lower segments no
doubt reflects the transition from coronal plane facets to sagittal
plane facets.
Rotational movements in the thoracic spine are also �coupled with lateral flexion. In the upper thoracic spine, rotation is
�coupled with same-side lateral flexion. This leads to MI gliding of
the inferior facet relative to the superior facet on the side of trunk
rotation and LS gliding of the inferior facet on the side opposite
trunk rotation. The coupling is not as marked in the lower segments
as it is in the upper segments.6 This may occur because the facets of
the lower thoracic spine become more sagittal in their orientation.
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191
C2−T1
T1−T4
T4−T8
Figure 5-116â•… Horizontal view, illustrating right rotation of the supeT8−L1
L1−L4
L1−S1
L4−L5
L5−S1
Figure 5-115â•… Coupled relationship of lateral flexion and axial rota-
tion throughout the spine. The cervical and upper thoracic regions have
lateral flexion coupled with ipsilateral rotation, and the lumbar spine and
lower thoracic regions have lateral flexion coupled with contralateral rotation. (From White AA, Panjabi MM: Clinical biomechanics of the spine,
ed€2, Philadelphia, 1990, JB Lippincott.)
Kinetics of the Thoracic Spine
The same principles of concentric and eccentric muscle activity
discussed for the cervical spine apply to the trunk. Nonsegmental
muscles can induce movement of the entire thoracic spine or act
segmentally. They include the erector spinae, rectus abdominis,
quadratus lumborum, and abdominal obliques. The segmental muscles that influence each thoracic motion segment include
multifidi, interspinalis, intertransversarii (small in the thoracic
segments), and rotatores.
Flexion is initiated by concentric activity of the rectus abdominis and controlled or limited by eccentric activity of the erector spinae. Flexion is further limited by the elastic limits of the
rior vertebra (light) relative to the inferior vertebra (dark).
�
myofascial
tissue, ligamentum flavum, interspinous ligament,
supraspinous ligament, PLL, capsular ligaments, posterior IVD,
and bony impact of the vertebral bodies.
Extension is initiated by concentric activity of the erector
spinae and controlled or limited by eccentric activity of the rectus
abdominis. Extension is mainly limited by the bony impact of the
spinous and articular processes, but the ALL, anterior IVD, and
elastic limits of myofascial tissue also contribute.
Lateral flexion is initiated by concentric activity of ipsilateral
erector spinae and quadratus lumborum and controlled or limited
by contralateral eccentric activity of the same muscles. Further
limiting of lateral flexion movement occurs through impact of the
articular facets, contralateral capsular, ligamentum flavum, intertransverse ligament, and elastic limits of contralateral segmental
and nonsegmental muscles.
Rotation is initiated by concentric activity of ipsilateral
erector spinae, multifidus, and rotatores and controlled or
limited by concentric and eccentric activity of the abdominal obliques and erector spinae. Rotation is further limited
by the articular capsules, interspinous ligament, supraspinous
ligament, ligamentum flavum, bony impact of the articular
facets, and elastic limits of bilateral segmental and nonsegmental muscles.
Functional Anatomy and
Biomechanics of the Rib Cage
The rib articulations can be divided into two groups, one connecting the heads of the ribs to the vertebral body (costovertebral
joints) and one connecting the necks and tubercles of the ribs with
the transverse process (costotransverse joints). The costovertebral
joints of ribs 1 and 10 to 12 articulate with a single �vertebral body.
In the remaining costovertebral joints, the rib heads articulate
with adjacent vertebral bodies. A facet on the posterior tubercle
of the ribs and a corresponding facet on ribs 1 to 10 form the costotransverse articulations. Ribs 11 and 12 do not have costotransverse articulations.
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| Chiropractic Technique
Costotransverse
articulation
Rib
Rib head
Transverse
process
Superior
articular
facet
A
B
C
Figure 5-119â•… The effects of lateral flexion (A), flexion (B), and
extension (C) on the shape of the rib cage.
Costovertebral
articulation
Figure 5-117â•… Axial view of a thoracic vertebra with rib attachments.
Sternochondral
joints
Costochondral
joints
Radiate
sternocostal
ligaments
�
Intercostal
ligaments
L
Figure 5-118â•… Anterior attachments of the ribs to the sternum: 2 to 7
directly and 8 to 10 indirectly via costocartilage.
The articulations that are formed between the vertebral and
costovertebral bodies and the transverse and costotransverse processes are each tightly secured by ligaments (Figure 5-117). Both
of these articulations are true synovial joints. The costotransverse
articulation is surrounded by a joint capsule, with further strength
from the costotransverse ligaments. The costovertebral articulations have a single capsular ligament surrounding the two demifacet articulations, which are further strengthened by the radiate
ligament.
These synovial joints are prone to the same pathologic conditions that affect other synovial joints, including the subluxation
and dysfunction complex. Furthermore, the ribs play an integral
part in the normal activity of the thoracic functional unit and
should be a significant consideration in evaluation for thoracic
dysfunction.
Anteriorly, the first seven ribs connect to the sternum directly, and
the eighth, ninth, and tenth ribs attach indirectly via the costocartilage (Figure 5-118). The eleventh and twelfth ribs are free floating,
with no anterior attachment. The anterior articulations move mainly
because of the elastic quality of the costocartilage. Calcification
and subsequent decreases in movement can occur with age.
Movements of the Rib Cage with Spinal Movements
The ribs influence movement of the individual thoracic vertebrae,
and the rib cage influences the movement of the entire thoracic
spine. With flexion and extension, the ribs move correspondingly
R
Figure 5-120â•… The effects of right rotation of a thoracic vertebra on
its associated rib, leading to accentuation of the posterior concavity of the
rib on€the side of vertebral rotation and flattening of the posterior concavity of the rib€on the€opposite side. (From Kapandji IA. In: The physiology
of the joints, ed 2, vol 3, Edinburgh, 1974, Churchill Livingstone.)
with the thoracic spine, resulting in the posterior intercostal spaces
opening up with flexion and closing with extension. The entire rib
cage must flatten superiorly and inferiorly, increasing the sternal
angle, for flexion of the thoracic spine to take place. The converse
is true for extension (Figure 5-119). A similar relationship occurs
with lateral flexion as the rib cage is depressed on the side of lateral
flexion. Furthermore, the lateral intercostal spaces open on the
convex side and close on the concave side. With thoracic rotation,
the rib angle is accentuated on the side of posterior trunk rotation,
and flattening of the rib angle occurs on the side of anterior trunk
rotation (Figure 5-120).
Movements of the Rib Cage with Respiration
Individually and collectively, the ribs undergo two main types
of motion during respiration. These movements are commonly
referred to as bucket handle and pump handle movements.
Bucket-handle movement increases the transverse diameter
of the rib cage by elevating the rib and its costochondral arch
(Figure 5-121). Bucket-handle movement is greater in the lower
thoracic spine, where the relatively flat tubercular facets of the
ribs and corresponding articular facets of the transverse processes
allow the rib to ride up and down against the transverse process.
The lower ribs may therefore roll around an axis connecting the
�costovertebral and sternochondral joints. This allows for �elevation
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193
x-y axis
A
B
C
D
Figure 5-121â•… Movements of the ribs. A, Axial view of pump-handle movement, with the rib rotating around the x-y axis, elevating the rib in front.
B, Lateral view, demonstrating elevation of the rib and anterior-to-posterior expansion of the rib cage. C, Bucket-handle movement, �illustrating transverse expansion of the rib cage.
and �depression of the ribs with respiration and a movement that
simulates the rolling movement of a bucket handle when it is
�elevated on its hinges.29
Pump-handle movement increases the A-P diameter of the rib
cage. It occurs more in the upper rib cage than in the lower and
results from the elevation of the anterior aspect of the rib cage
with the upward and forward movement of the sternum. In contrast to the lower ribs, the tubercular facets of the upper ribs are
situated in deep cup-shaped sockets on the transverse processes.
Therefore, the rib is free to move only along the axis that �connects
the costovertebral and costotransverse joints. With inspiration,
the rib head rolls downward, elevating the anterior end of the rib
like the handle of a pump28 (see Figure 5-121).
Kinetics of Respiration
During quiet respiration, thoracic mobility is minimal because
the diaphragm is the main muscle of respiration. The intercostal
muscles are slightly active to supply tension, and the quadratus
lumborum fixes the twelfth rib to provide a stable attachment.
However, during forced respiration, the external intercostal muscles become active to elevate the ribs and receive secondary help
as needed from the scaleni, pectoralis minor, serratus anterior, and
iliocostalis cervicis.
Expiration is usually a passive process resulting from the elastic tension produced in the ribs, costocartilage, and pulmonary
parenchyma. Forced expiration is produced by the internal intercostal muscles, which receive secondary help from the abdominal muscles, iliocostalis lumborum, longissimus, and quadratus
lumborum. The activity of the expiratory muscles is also used
to perform the Valsalva maneuver, increasing intra-abdominal
pressure.
Upper rib dysfunction is theorized to be associated with ribs
fixated in a superior (flexed) position, as a result of the pull of
the iliocostalis cervicis, longissimus cervicis, scalenes, and serratus
posterior and superior muscles. Similarly, because of the effects of
the longissimus thoracis, iliocostalis lumborum, quadratus lumborum, and serratus posterior and inferior muscles, the lower ribs
tend to be pulled and fixated inferiorly. However, the iliocostalis
thoracis muscle may produce the opposite movement in each area,
depressing the upper ribs and raising the lower ribs.
Functional Anatomy and
Characteristics of the
Transitional Areas
The thoracocervical (C6–T3) and thoracolumbar (T10–L1)
�segments form a transition between the thoracic spine and the
�cervical and lumbar regions. Hence, some characteristics or �activities
are shared by both regions and some are unique to each region.
Thoracocervical Junction (C6–T3)
The notable structural changes in this segment include spinous
processes that become more elongated, point caudally, and lose
the bifid characteristic of the cervical spine. Furthermore, there are
no uncinate processes or transverse foramen. The upper �thoracic
segments include costotransverse and costovertebral articulations,
as well as an increased slope to the articular facets.
Because of the distal attachment of the cervical muscles, including the splenius, longissimus, and semispinalis cervicis, as well as
the semispinalis capitis muscles, cervical spine movements involve
the upper thoracic spine. The ribs in this area provide stability but
also decrease motion. Movements in all directions are decreased
between C6 and T3, but the coupled movements in this area are
the same as for the typical cervical region (e.g., lateral flexion is
coupled with rotation to the same side).
The significance of this area is twofold. First, this area is structurally and functionally related to the neurovascular structures of
the upper extremities, because this area forms the thoracic outlet (Figure 5-122). Second, the thoracocervical junction has been
deemed a difficult area to apply manipulative therapy. This reputation has been established because of the necessary structural characteristics for a transition from the most mobile area of the spine
to the area that is significantly less mobile, as well as the external
characteristics of distribution of body fat (dowager hump) and the
shoulder and scapular muscles.
Thoracolumbar Junction (T10–L1)
The thoracolumbar transition area is similar to the thoracocervical junction in that it must serve to join an area of greater
mobility with one of lesser mobility, as well as change from a primary (kyphotic) curve to a secondary (lordotic) curve. The most
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| Chiropractic Technique
9
10
Scalenus anterior
11
Middle trunk
of brachial plexus
12
Lower trunk
L1
2
3
1st rib
4
Scalene tubercle
Right subclavian
artery
5
Figure 5-122â•… The cervicothoracic junction and its relationship to
S1
2
3
the neurovascular bundle. (From Grieve GP: Common vertebral joint
problems, ed 2, Edinburgh, 1988, Churchill Livingstone.)
4
5
T 10
A
T 11
T 12
L1
L2
Figure 5-123â•… The thoracolumbar transition is characterized by a
change in facet planes from coronal to sagittal.
�
significant
structural characteristic in this area is the change from
the coronal facet plane in the thoracic spine to the sagittal plane
facets in the lumbar spine (Figure 5-123). This transition, although
typically thought to occur at the T12–L1 segment, has been shown
to occur at any of the segments between T10 and L1. Davis30
reported the change was found to occur most commonly at the
T11–12 level (Table 5-5).
Of further clinical importance is the distribution of the lateral branches of the posterior primary rami of the spinal roots
of T12–L2. These nerves form the cluneal nerves and innervate
the skin and superficial structures of the upper posterolateral
buttock, posterior iliac crest, and groin area (Figure 5-124).
Dysfunction within the lower thoracic segments may refer pain
into these regions and be mistaken for disorders of the lumbosacral or sacroiliac regions, which also commonly refer pain to
these zones. Maigne31 believes this �syndrome can account for up
to 60% of chronic and acute backache, �generally considered the
result of lumbar or sacral joint changes.
B
Figure 5-124â•… The course of the cluneal nerves (A) and possible
distribution of pain findings and sensory changes (B). (A from Grieve
GP: Common vertebral joint problems, ed 2, Edinburgh, 1988, Churchill
Livingstone. B from Basmajian JV: Manipulation, traction and massage,
ed 3, Baltimore, 1985, Williams & Wilkins.)
TABLE 5-5
Segment
T10–11
T11–12
T12–L1
Total
F requency of Lower Thoracic
Segments Demonstrating Transition
from Coronal Facets to Sagittal
Facets
Percentage
7.46
68.66
23.88
100.00
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
Evaluation of the Thoracic Spine
TABLE 5-6
Observation
Before palpation is begun, a visual examination should be made to
observe for any deviations in posture or symmetry. Postural syndromes that may predispose the patient to spinal dysfunction and
pain are common in the thoracic spine and should not be �overlooked.
Idiopathic scoliosis has its greatest expression in the thoracic spine,
and any noted curvatures should be assessed for flexibility.
Alignment in the coronal plane is evaluated by observing the
orientation of the spinous processes, symmetry of paraspinal soft
tissues, and contours of the rib cage. The alignment of the shoulders and angles of the scapula should be observed and compared
relative to the iliac crests. Sagittal plane alignment is assessed by
observing the status of the thoracic curve and noting the position
of the gravity line. Orientation of the trunk in the transverse plane
is noted by looking at the shoulders and vertebral borders of the
scapula for any winging (Figure 5-125).
Global motion of the thoracic spine is typically not separated
from lumbar movements. Both are measured and recorded as
movements of the entire trunk. However, when desired, regional
movements of the thoracic spine may be assessed with the inclinometric measuring methods previously described in Chapter 3 (see
Figure 3-10). Table 5-6 presents the average global ROMs for the
thoracic spine.
A
B
Figure 5-125â•… Postural evaluation. A, Posterior plumb line, demonstrating shoulder and pelvic unleveling creating a C-shaped scoliosis.
B, Lateral plumb line, demonstrating a round back deformity with an
anterior shift in the gravitational line.
195
lobal Range of Motion for the
G
Thoracic Spine
Flexion
Extension
One-Side Lateral
Flexion
One-Side Rotation
25–45 degrees
25–45 degrees
20–40 degrees
30–45 degrees
Static Palpation
Static palpation of the spine and posterior chest wall is commonly performed with the patient in the prone position. During
the evaluation, stand to the side of the patient and accommodate
the patient by bending at the knees, hips, and waist. Palpation
�typically begins with an assessment of superficial temperature
and sensitivity, followed by the assessment of consistency and
mobility of the dermal layer and muscular layer. Palpation of
bony landmarks incorporates a scanning assessment of contour,
tenderness, and alignment of the spinous processes, transverse
processes, rib angles, interspinous spaces, and intercostal spaces.
In addition, the alignment of the scapula and its borders and
angles is customarily included in the evaluation of the thoracic
spine.
Potential tenderness and alignment of the spinous processes,
interspinous spaces, and transverse processes are assessed with unilateral or bilateral fingertip contacts (Figures 5-126 and 5-127).
Paraspinal muscle tone is evaluated by applying bilateral contacts
with the palmar surfaces of the fingers or thumbs to explore for
areas of tenderness and altered muscle tone and texture (see Figure
5-127).
Rib alignment and tenderness is assessed by palpating along
the rib angles with the fingertips or thumb. Palpation may be conducted with the patient in the sitting or prone position. The sitting evaluation has the advantage of being able to induce trunk
rotation to accentuate the ribs for palpation. When rib alignment
is assessed in the sitting position, the patient is asked to cross the
arms over the chest and flex slightly forward. The doctor then sits
or stands beside the patient and rotates the patient forward on the
side to be palpated (Figure 5-128).
The rib angles should be uniform in prominence and not tender. A tender or distinctly palpable lump that stands out in relation to the adjacent ribs may indicate rib dysfunction. Take care
to differentiate a prominent rib from a myofascial trigger point
(the former is bony and immobile; the latter softer and more
mobile). The pain associated with costotransverse dysfunction is
often accentuated with respiration and may radiate to the anterior chest wall. Dysfunction of the costosternal junction may also
be present with or without posterior �dysfunction. Evaluate the
anterior chest wall for myofascial or joint dysfunction when the
patient complains of pain of the posterior or anterior chest wall.
Motion Palpation
Joint Play. The thoracic spine should be scanned for sites
of �painful or abnormal JP with the patient sitting or prone.
Areas of€elicited abnormality should be further assessed with
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| Chiropractic Technique
A
B
Figure 5-126â•… Palpation of rotational alignment and sensitivity of thoracic spinous processes (A) and interspinous spaces and sensitivity (B).
A
B
Figure 5-127â•… Palpation of transverse process alignment and paraspinal soft tissue tone, texture, and sensitivity using fingertip contacts
(A) and thumb contacts (B).
�
counter-rotational
JP procedures. With the patient in the prone
position, P-A glide is assessed by establishing contacts over
the spinous process or bilaterally over the transverse processes.
P-A pressure is gradually applied and a springing motion is
created. During P-A JP assessment, a subtle pain-free gliding
and recoil should be felt at each level tested (Figures 5-129
and 5-130).
To further isolate the specific level of pain and possible dysfunction, counter-rotational JP and provocation testing may be
applied. To perform this procedure, place thumbs on opposing
sides of adjacent spinous processes and apply springing pressure
toward the midline (Figure 5-131). This procedure is less giving
than A-P glide, and a perceptible decrease in movement is encountered when pressure is applied to adjacent vertebrae. Pain elicited
at one level and not at adjacent levels helps localize sites of possible dysfunction.
If desired, this procedure may be performed with the contacts
located over the transverse processes instead of the spinous processes. Precise location of landmarks is more difficult with this
method, but it may provide an acceptable alternative in circumstances in which the patient’s spinous processes are tender to light
palpation (Figure 5-132).
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
197
Figure 5-130â•… Prone midthoracic joint play
5-130
evaluation, using bilateral thenar contacts over the
transverse processes and applying a posterior-to-anterior vector of force.
Figure 5-128â•… Palpation of the right T6 rib angle.
Figure 5-131â•… Counter-rotational joint play
5-131
evaluation for left rotational movement of T7 relative to T8. Opposing forces are directed toward the midline through a
contact established on the right side of the T8 and the left side of the T7
spinous process.
Figure 5-129â•… Prone midthoracic joint play
5-129
evaluation, using bilateral fingertip contacts over the
transverse processes and applying a �posterior-to-anterior vector of force.
Segmental Motion Palpation and End Play. Movement
is typically evaluated with the patient in the sitting position,
with arms flexed and folded across the chest so that the hands
can grasp the opposing shoulders. The doctor’s position may
be sitting behind or standing beside the patient; the standing
position is usually preferred when the upper thoracic segments
are evaluated. Movement is controlled through contacts on
the patient’s shoulders for the middle and lower thoracic segments or on the crown of the patient’s head when the upper
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| Chiropractic Technique
Figure 5-132â•… Counter-rotational joint play evaluation for right rotational movement of T5 relative to T6. Opposing forces are directed posteriorly to anteriorly over the right T6 transverse process and left transverse
process of the T5.
�
thoracic
segments are evaluated (Figure 5-133). IH contacts
on the patient’s head are to be avoided in patients with cervical complaints.
Rotation.╇ The segmental contact is established against the
lateral surface of the adjacent spinous process on the side of
induced rotation. The palpating thumb is placed so that the
A
5-133A, B
pad spans the interspinous space. The support hand reaches
around the front of the patient and grasps the opposite flexed
arm or shoulder and rotates the patient’s trunk toward the side
of contact (see Figure 5-133). During normal rotation, the superior spinous process should be palpated, rotating away from the
spinous process below. Movement should occur in the direction of
trunk rotation. If �separation is not noted and adjacent spinous processes move together, segmental restriction should be suspected.
To assess end play, additional overpressure is applied through
the contact and IH at the end of passive motion. Firm �elastic but
giving motion should be encountered. Contacts may be established
against the superior spinous process on the side of induced rotation (see Figure 5-133) or over the transverse �process and posterior
joint on the side opposite the induced rotation (Figure 5-134).
Lateral Flexion.╇ To assess lateral flexion, a segmental �contact
against the lateral surface of the adjacent spinous processes is
�established on the side of induced lateral flexion. The doctor either
sits or stands behind the patient toward the side of induced lateral flexion. If a sitting position is selected, movement is guided by
placing the forearm across the patient’s shoulders (Figure 5-135). In
the standing position, movement is directed by placing the doctor’s
hand on the patient’s shoulder on the side of induced lateral flexion
(Figure 5-136). In the lower thoracic spine, slight patient flexion
is produced to accentuate the spinous process and reduce coupled
rotation.
Movement is induced by asking the patient to bend to the side
as downward pressure is applied through the indifferent arm. As
bending is being actively produced, medial pressure is applied
through the contact hand to help accentuate the �bending at the site
of palpation. The indifferent arm and contact arm work together
to isolate the site of lateral flexion by adjusting the amount of
B
Figure 5-133â•… Palpation of left rotational movement at the T7–8 level (A) and the T2–3 level (B), using a thumb contact across
the left interspinous space.
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
5-134
199
Figure 5-134â•… Palpation of left rotational end
play over the T7–8 articulation.
Figure 5-135â•… Palpation of left lateral flexion
5-135
movement at T6–7, using a thumb contact across the
left T6–7 interspace, with the doctor seated.
5-136
Figure 5-136â•… Palpation of left lateral flexion at
the T6–7 level, with the doctor standing.
applied downward pressure and tilting of the patient. During
this movement, the spinous process should be felt to shift toward
the opposite side (convex side) while the spine bends smoothly
around the contact point (CP). End play is evaluated by applying
additional overpressure at the end ROM.
Flexion and Extension. The segmental contacts are established over the interspinous spaces with the doctor’s fingertips or
thumb. When flexion and extension in the upper thoracic spine
are �evaluated, movement is guided by placing the IH on the crown
of the patient’s head (Figure 5-137).
When evaluating flexion or extension in the middle to lower
thoracic segments, ask the patient to overlap or interlace his or her
fingers behind the neck. To evaluate flexion, place your indifferent
forearm across the patient’s shoulder, or grasp the patient’s flexed
elbows to help guide movement. To evaluate extension, place your
forearm beneath the patient’s flexed arms and apply a lifting action
to assist in the development of extension (Figure 5-138). To assess
motion, actively or passively flex and extend the spine. Take care
to place the apex of bending at the level of palpation. During
�flexion, the interspinous spaces should open symmetrically, and
during extension, they should approximate.
Flexion end play is assessed by maintaining palpatory contact
with the inferior aspect of the superior spinous process while gentle downward pressure is applied through a forearm contact on
the patient’s shoulders. Extension end play is evaluated by pushing anteriorly after full extension has been reached. Extension end
play is inhibited by the impact of the spinous processes and has a
more rigid quality than flexion, lateral flexion, or rotation.
Rib Motion Palpation
Ribs 3 to 12. The evaluation of rib mobility incorporates an assessment of bucket-handle movement and costotransverse end play.
End play is assessed by placing the patient in the sitting �position
and inducing slight flexion, lateral flexion, and rotation of the
patient forward on the side of palpation. The palpation contact is established with the doctor’s thumb or fingertips over the
rib angle, just lateral to costotransverse articulation. The doctor
reaches around with the nonpalpating hand to grasp the patient’s
shoulder and induce rotation. The patient is rotated and the rib
is stressed posteriorly to anteriorly at the end of rotation (Figure
5-139). A rib that remains distinctly prominent and �provides firm
resistance relative to adjacent segments indicates rib dysfunction.
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| Chiropractic Technique
A
5-137
Figure 5-137â•… Palpation of extension movement (A) and flexion movement (B) in the upper thoracic spine, using fingertip
contacts in the interspinous spaces.
A
5-138
B
B
Figure 5-138â•… Palpation of extension movement (A) and flexion movement (B) in the middle thoracic spine, using fingertip
contacts in the interspinous spaces.
To assess bucket-handle motion, the doctor places his or her
fingertips in the intercostal spaces at the midaxillary line. The doctor’s indifferent arm is placed across the patient’s shoulders, and
the patient is laterally flexed toward and away from the side of
contact (Figure 5-140). The intercostal spaces should open with
lateral flexion away from and close with lateral flexion toward the
contacts. Absence of symmetric opening and closing may indicate
dysfunction at the costotransverse joint or stiffness in the intercostal soft tissues.
Ribs 1 and 2. To evaluate mobility of the upper two ribs, place
the patient in a sitting position and contact the PS portion of the
first or second rib with the fingertips. The IH grasps the crown of
the patient’s head, rotates it away from the side being palpated,
and laterally flexes and extends the head toward the side being
palpated (Figure 5-141). During this motion the rib should drop
inferiorly and seem to disappear. Dysfunction should be suspected
if the rib remains prominent and immobile during the passive
movements of the head.
Anterior Rib Dysfunction. To evaluate movement of the costosternal joints and anterior intercostal spaces, place the patient
in the sitting position and stand behind the patient while contacting the intercostal spaces just lateral to the sternum. Take
care to avoid contact with the breasts of female patients. Flex
the patient’s elbow and shoulder on the side of palpation and
grasp the elbow (Figure 5-142). Move the patient’s flexed arm
into further flexion and palpate for opening of the intercostal
spaces (e.g., the superior rib should move cranially in relation to
the inferior rib).
Overview of Thoracic Spine Adjustments
Prone Adjustments
Prone thoracic adjustments are characteristically direct short-level
methods (Figure 5-143). They have the advantage of providing
effective and specific access to points of contact while allowing
Figure 5-139â•… Palpation of posterior-to-anterior
5-139
end play of the right T7 rib articulation, using a
thumb contact over the right T7 rib angle.
Figure 5-141â•… Palpation of the first rib, using a
5-141
fingertip contact over the superior aspect of the
angle of the right first rib.
A
Figure 5-142â•… Palpation of right anterior rib mobility, using a fingertip contact in the right anterior intercostal spaces.
B
Figure 5-140â•… Palpation for bucket handle rib
5-140
movement. A, Starting position, with fingers in the
intercostal spaces in the midaxillary line. B, Left lateral flexion movement to
evaluate opening of the right intercostal spaces.
5-143
Figure 5-143â•… Prone unilateral hypothenar
transverse adjustment.
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| Chiropractic Technique
for positions that maximize posterior to anterior incorporation
of the doctor’s body weight in directing and delivering adjustive
thrusts.
Although they are commonly delivered with the patient in a
relatively neutral position, it is possible to modify prone positioning to induce positions that assist in the development of preadjustive tension and the desired movement. Elevation of the
thoracolumbar section of an articulating table or Dutchman roll
may be used to develop segmental flexion, and the thoracolumbar
section may be lowered to induce extension. Placing the patient
on his or her forearms on an adjustive bench can also be used
to induce more preadjustive segmental extension. Lateral flexion
may be induced by bending the patient to the side or by sidebending a flexion table. Rotation of the trunk is not practical on
most adjusting€ tables, although some rotation may be induced
with rotation of the pelvic section of flexion tables.
After the patient is appropriately positioned and the contacts are established, the doctor reduces articular slack by transferring additional body weight into the contact. At tension, the
adjustive thrust may be generated solely through the arms but
more �frequently incorporates a combined body-drop and arm
thrust.
Knee-Chest Adjustments
Knee-chest adjustments are similar to prone thoracic adjustments
(Figure 5-144). In most cases, the only difference is the modification in positioning the patient must undergo on the knee-chest
table. Knee-chest adjustments may be applied to any region of the
thoracic spine and under many of the same circumstances as prone
thoracic adjustments. However, they are probably most effectively
applied in the treatment of lower thoracic extension restrictions
(flexion malpositions). The knee-chest table does not restrict thoracolumbar extension and therefore allows the doctor to maximize
movement into extension. Although it does provide for maximal
extension, it also makes the patient vulnerable to hyperextension.
Consequently, the doctor must be skilled in this procedure and
apply it only with shallow, gentle, nonrecoil thrusts.
Figure 5-144â•… Knee-chest hypothenar spinous adjustment.
Sitting Adjustments
Sitting thoracic adjustments afford the doctor the opportunity to
modify patient position in the development of preadjustive tension
(Figure 5-145). They are typically applied as assisted adjustments
with the adjustive contact established on the superior vertebra.
The IH contacts the anterior forearm to assist in the development
of appropriate trunk rotation. At tension, both hands thrust to
induce motion in the direction of restriction to induce distraction at the motion segments below the level of contact. They are
most commonly applied for rotational restrictions in the middle
to lower thoracic spine but may be applied for combined rotation
and lateral flexion restrictions.
Supine Adjustments
The effectiveness of supine adjustive techniques is a controversial topic within chiropractic. A number of chiropractic colleges
have limited or no instruction in supine techniques, and a significant percentage of practicing chiropractors also object to their
application. The basis for this position appears to be related to
the contention that supine techniques are less specific and therefore less effective. Unfortunately, this contention has led to a lack
of investigation and understanding of the appropriate application of supine techniques. We believe supine techniques should
not be dismissed out of hand. They can be effective if applied
in the proper circumstances, and they should be considered for
incorporation in the management of thoracic dysfunction. Supine
techniques allow the doctor the opportunity to significantly modify patient position. Predisposing patients into the direction of
desired �movement restriction may be helpful in producing the
desired adjustive movement and effect. Supine techniques also use
the patient’s body weight to assist the doctor in developing preadjustive tension and adjustive force. Their major Â�disadvantage is
access to posterior spinal CPs and the close physical contact that is
generally required between the doctor and patient.
One of the major distinctions between prone and supine adjustive techniques is the activity of the posterior spinal contacts. In
supine techniques, the posterior contact is customarily passive and
provides a fulcrum point for localizing the site of preadjustive tension and reactive adjustive force.
5-145
Figure 5-145â•… Sitting thoracic hypothenar transverse
adjustment.
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
The adjustive impulse in supine technique is generated by
thrusting with the weight of the doctor’s torso through the patient
toward the posterior contact (Figure 5-146). The adjustive thrust
accelerates the patient toward the posterior contact and generates
a force back toward the patient’s spine as the posterior contact
meets the firm resistance of the adjustive table.
Supine adjustive techniques also involve a potential component
of axial traction applied during the development of preadjustive tension and delivery of an adjustive impulse. Long-axis traction may aid
in the distraction of the posterior joints and is helpful in minimizing
unnecessary compression to the patient’s rib cage. The doctor generates this force by incorporating a small headward (I-S) orientation
and movement as he or she develops preadjustive tension.
The positions of the posterior hand contacts vary depending on the area of application and the dysfunction being treated.
The optional hand positions (Figure 5-147) and the appropriate
�application of each are discussed under each specific adjustment.
When applying a bilateral transverse contact, the spinous processes rest in the midline of the doctor’s cupped hand or clenched
fist as the thenar and phalanxes contact each side of the patient’s
spine over the transverse process. Care must be taken to ensure the
contacts are established medial to the rib angles and equally balanced. When developing contacts in the lower thoracic spine, it is
important to place the hand in a more vertical position to bridge
the distance between the table and the patient.
A
D
Figure 5-146â•… Supine thoracic adjustment, using
5-146
B
203
a clenched fist for the posterior contact.
C
E
Figure 5-147â•… Optional hand positions for supine thoracic adjusting. A, Clenched fist, where the thenar and index contacts are established bilaterally over
the vertebral transverse processes. B, Open palm, where the thenar and hypothenar contacts are established bilaterally over the vertebral transverse processes.
C, Open palm, where the thenar contact is established against the inferior tip of the spinous process. D, Open palm, where the index contact is established
against the inferior tip of the spinous process. E, Open palm, where the thenar contact is unilaterally established over the vertebral transverse process.
204
A
| Chiropractic Technique
B
C
Figure 5-148â•… Optional patient arm positions in the supine thoracic
adjustment. A, Right arm crossed over left. B, Crossed-arm position to
separate the scapula and decrease posterior-to-anterior depth of torso.
C, Pump-handle position.
Supine adjustive techniques also allow for a variety of optional
patient arm placements (Figure 5-148). The positioning of the
patient’s arms is mainly a matter of doctor discretion. However,
when crossing the patient’s arms across the chest, it is important
to consider both patient and doctor comfort. To reduce the stress
to the patient’s anterior chest or breasts, a small sternal roll may be
placed between the patient’s crossed arms. To lessen the pressure
against the doctor’s upper abdomen or chest, a rectangular pillow
may be placed between the patient’s crossed arms and the doctor.
When using crossed-arm positions in large patients, it is helpful to cross the arms in a manner that decreases the combined A-P
diameter of the patient’s thorax. Positions that cross only one arm
over the chest or cross the opposing forearm beneath the other
(Figure 5-148, B) decrease the A-P distance. Positions that interlace crossed arms (Figure 5-148, A) tend to produce more padding for the patient’s anterior chest but tend to increase the A-P
Â�distance from the patient’s forearms to the table.
Standing Adjustments
Standing thoracic adjustments use the same mechanical principles as supine thoracic adjustments (Figure 5-149). More significantly, they provide positions that allow the doctor to use the
strength of his or her legs in developing preadjustive tension and
the adjustive impulse. When applying standing methods, it is
important to direct the adjustive force in an A-P and I-S direction
to avoid uncomfortable compression of the patient’s upper abdomen. Standing adjustments may be difficult to perform in acute
patients who cannot withstand weight-bearing and are impractical in situations in which there are large discrepancies in height
between doctor and patient.
Rotational Adjustments
Rotational dysfunction of the thoracic spine may result from
decreased mobility in the posterior joints and associated soft
�tissues on one side or both sides of the involved motion segment
(Figure 5-150). The side and site of fixation are assessed by comparing each side for subjective and palpatory pain, soft tissue texture asymmetry, and end-play quality.
Rotational dysfunction may be treated with prone, supine,
standing, or sitting adjustive methods. Prone methods most commonly use assisted contacts, but methods that apply counterthrust
contacts are also frequently used. Resisted methods are not commonly applied in prone patient positions.
5-149
Figure 5-149â•… The standing thoracic adjustment.
Assisted methods are applied with the doctor establishing
contacts over the transverse process or spinous process of the
superior segments (Figures 5-151 and 5-152). Resisted methods
use contacts applied over the transverse or spinous process of
the inferior segments (Figures 5-153 and 5-154). Counterthrust
methods use contacts applied over the adjacent transverse process (Figure 5-155). When using bilateral contacts, the doctor
has the option of making one hand active and one hand passive or of making both hands active. Counterthrust methods use
active thrusts through both CPs. Counterstabilizing methods
use one active hand and one countersupporting and nonthrusting contact.
When rotational dysfunction is treated, it may be more effective to use bilateral contacts on adjacent vertebral segments as
compared with unilateral contacts (see Figure 5-155. This should
help isolate the adjustive forces to the site of fixation and reduce
tension to adjacent joints.
Prone resisted adjustive methods are commonly applied in the
upper thoracic spine (C7–T2). During the application of these
methods, the cervical spine is slightly laterally flexed away from
and rotated toward the direction of restriction (see Figure 5-153).
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
205
1
2
A
B
Figure 5-150â•… A, Transverse view of right rotation at T5–6, showing gliding movement of the left articulation (Box 1) and gliding and end-play gapping of the right articulation (Box 2). B, Coronal view, illustrating the coupled right lateral flexion associated with right rotation at T5–6, with superior
glide of the left T5 articular surface relative to T6 and inferior
�
glide of the right T5 articular surface relative to T6.
T4
T5
T6
T7
T3
5-151
T8
Figure 5-151â•… Hypothenar transverse contact applied to the right transverse process of T6 to induce left rotation or left lateral
flexion of the T6–7 motion segment.
Medial and inferior glide
T3
T4
T5
Right
Left
Distraction
5-152
Figure 5-152â•… Unilateral hypothenar contact applied to the right lateral surface of the T3 spinous process (dot) to induce right
rotation or right Â�lateral flexion in the T3–4 motion segment. Arrows indicate direction of adjustive thrust.
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| Chiropractic Technique
Figure 5-153â•… Resisted method. Hypothenar contact applied to the left transverse process of T2 (dot) or right spinous process
5-153
of T2 (x), resisted by counter-rotation and lateral flexion of the segments above. Depicted is a procedure for treatment of a left
rotation and/or coupled right lateral flexion restriction at T1–2 with distraction of the left T1–2 articulation. Arrows indicate the direction of motion
induced during the application of the procedure.
T3
Gapping
T4
T5
Right
Left
Figure 5-154â•… Resisted unilateral hypothenar contact applied to the right transverse process of T4 (dot) to induce gapping in the right T3–4 articulation. The adjustive force (solid arrow) is directed posteriorly. The broken arrow and position of T3 illustrates the relative movement generated between
T3 and T4. It does not reflect any starting malpositioned state of T3. This procedure is not commonly applied.
T7
T6
T5
Left
Gapping
Right
Superior glide
Figure 5-155â•… Crossed bilateral contacts applied to the T5–6 motion segment to induce left rotation. The left hypothenar
5-155
contact is established over the left transverse process of T6 (dot) and the right thenar contact is established over the right transverse
process of T5. Solid arrows illustrated in the picture indicate direction of adjustive force, and the broken arrows illustrated in the diagram indicate the
motion induced in the T5–6 motion segment during the application of the procedure.
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
When applying resisted methods with transverse process contacts, the contacts are established on the side of rotational restriction. When applying resisted methods with spinous processes
contacts, the contacts are established on the side opposite the rotational restriction (see Figure 5-153). The inferior vertebral contact
applies counterpressure to induce pretension in the joints superior
to the level of contact. At tension, the adjustive thrust is delivered
through the contact hand as the IH applies countertraction headward. For example, if the doctor is treating a restriction in left
rotation at the T1–2 motion segment with a resisted approach,
the contact is established over the left transverse process of T2 or
the right lateral surface of the T2 spinous process. The superior
�segments and head are rotated into left rotation, and maximal tension should be generated in the motion segments superior to the
point of adjustive contact (T2) (see Figure 5-153).
207
When using sitting patient positions in the treatment of rotational dysfunction, it is customary to use assisted methods to aid
in the development of trunk rotation. In all assisted methods, the
adjustive contact is established over the superior vertebra, and
the€thrust is directed to induce distraction in the joint below the
contact (Figure 5-156).
When applying supine adjustments in the treatment of rotational dysfunction, either assisted or resisted methods may be used.
Assisted methods are applied to induce rotation at the segments
below the level of contact. Maintaining the patient in a position
of segmental flexion may assist the doctor in distracting the joints
below the level of contact (Figure 5-157). With resisted methods,
the doctor establishes a thenar contact over the �transverse process
of the vertebra inferior to the level of dysfunction. The contact
is established on the side of fixation with the patient’s shoulders
T5
T6
T7
T8
5-156
Figure 5-156â•… Unilateral hypothenar contact applied to the left T6 transverse process (dot) to induce right rotation or right
lateral flexion.
T1
T2
T3
T4
T5
T6
Figure 5-157â•… Assisted method. Unilateral thenar contact applied to the right transverse process of T3 to induce left rotation or
5-157
left lateral flexion in the T3–4 motion segment. Wedge illustrates the placement of the hand and thenar, and arrow illustrates the
direction of adjustive vector through the doctor’s trunk.
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1
2
Adjustive force
T2
T3
T4
T5
Figure 5-159â•… Coronal view of right lateral flexion showing gliding
distraction of the left articular surfaces (1) and gliding approximation of
the right articular surfaces (2).
Point of
gapping
Thenar contact
Figure 5-158â•… Resisted method. Unilateral thenar
5-158
contact applied to the right transverse process of T4 to
induce right rotation and gapping in the right T3–4 articulation.
rotated toward the side of contact (Figure 5-158). The contact
provides a block and fulcrum point to induce rotation in the joints
above the contact. The adjustive thrust is directed through the
doctor’s trunk toward the table to induce rotation and gapping in
the direction of trunk rotation at the segments above the contact
level (see Figure 5-158).
Lateral Flexion Adjustments
Lateral flexion dysfunction in the thoracic spine may result from
a loss of inferior glide and approximation of the facet joints
on the side of lateral flexion restriction or loss of opening on
the side opposite the lateral flexion restriction (Figure 5-159).
When treating lateral flexion restrictions in the prone position,
the doctor may establish a unilateral transverse process contact
on the superior vertebra on the side opposite the lateral flexion
restriction and thrust P-A and superiorly (Figure 5-160) or on
the side of lateral flexion restriction and thrust P-A and inferiorly. Lateral flexion dysfunction may also be treated in the prone
position with bilateral transverse contacts. When �applying this
method, the contacts are established on each side of the superior vertebra. The contact hand on the side of �lateral flexion
T4
T3
T5
T6
T7
T8
Figure 5-160â•… Hypothenar transverse contact
5-160
applied to the right transverse process of T6 to
induce right lateral flexion of the T6–T7 motion segment.
restriction drives anteriorly and inferiorly to induce inferior
glide while the other drives anteriorly and superiorly to induce
superior glide (Figure 5-161).
When using spinous contacts in the prone position (Figure
5-152)�, the �doctor establishes the contacts on the side of lateral
flexion restriction. The thrust is delivered anteriorly and medially
toward the midline to induce closure of the facets and disc on the
side of lateral flexion restriction.
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T6
5-161
T7
209
T8
Figure 5-161â•… Bilateral hypothenar contacts applied to the transverse processes of T7 (dots) to induce left lateral flexion at the
T7–8 joint.
In prone adjustive methods, with the patient positioned in
a neutral position, it is unlikely that the doctor’s hand contacts
can establish enough tension (grip) with the underlying structures to induce segmental lateral flexion.32 This suggests that
using approaches and patient positions capable of prestressing
the spine in the direction of desired spinal movement may be
preferable.
In prone upper thoracic spine adjustments, the doctor may
choose to use a resisted method. With resisted methods the contact is established on the lower thoracic segment, and preadjustive tension is developed by tractioning the cervical segments on
the side of adjustive contact (Figure 5-153). At tension, an adjustive thrust is directed anteroinferiorly with the contact hand as
countertension is directed through the indifferent contact. This
method is designed to separate and distract the joints above the
SCP.
If lateral flexion dysfunction is treated in the sitting, standing,
or supine position, assisted patient positions are commonly used.
The contacts are established on the transverse process of the superior vertebra on the side opposite the lateral flexion restriction,
and the patient is laterally flexed in the direction of restriction. In
the sitting position, the thrust is directed anteriorly and superiorly
(Figure 5-156); in the supine and standing positions, the thrust
is directed through the trunk posteriorly and superiorly. In the
supine and standing positions, the patient must be maintained in
a flexed position to assist in the distraction of the involved joint
(Figure 5-157).
A
B
Figure 5-162â•… Sagittal view of the middle thoracic segments in flexion with separation and gliding distraction of the facet joints (A) and
extension with gliding approximation of the facet joints (B).
Flexion and Extension Adjustments
Flexion and extension dysfunction may be treated with prone,
knee-chest, supine, or standing patient positions. Flexion
restrictions produce a loss of gliding distraction in the posterior joints, and extension restrictions produce a loss of inferior glide and approximation in the posterior joints (Figure
5-162).
To induce flexion in the prone position and distraction of
the posterior joints, the doctor commonly establishes contacts
against the transverse processes or spinous process of the superior
vertebra and directs an adjustive VEC anteriorly and superiorly
5-163
Figure 5-163â•… Assisted bilateral thenar contacts
applied to induce flexion of T7–8 motion segment.
(Figure 5-163). In the upper or lower thoracic spine, where superior vertebral contacts may be hard to maintain, the doctor may
contact the inferior vertebra of the involved motion segment.
With this method, the doctor faces caudally, and the adjustive
thrust is directed anteroinferiorly to induce separation superior
to the contact (Figure 5-164). In prone adjustive methods, with
the patient positioned in a neutral position, it is unlikely that
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| Chiropractic Technique
Figure 5-164â•… Assisted bilateral thenar contacts applied to T8 to
induce flexion of the T7–8 motion segment.
T3
T4
the doctor’s hand contacts can establish enough tension (grip)
with the underlying structures to induce segmental flexion.32
This suggests that using approaches and patient positions capable
of �prestressing the spine in the direction of desired spinal movement may be preferable.
Supine adjustive postures may be more effective in the treatment of flexion restrictions by allowing for the production
and maintenance of spinal flexion. The adjustive contacts may
be established on either the superior or inferior vertebra of the
involved motion segment while the patient is maintained in a
position of segmental flexion. Superior (assisted) vertebral contacts are designed to distract the motion segments inferior to the
level of the contact hand (Figure 5-165). Inferior vertebral contacts are designed to distract the motion segments superior to the
level of contact.
With superior vertebral contacts, the doctor establishes contacts with an I-S tissue pull, and an S-I tissue pull is used with
inferior vertebral contacts. To develop preadjustive tension, the
doctor leans into the patient directing the patient’s trunk into the
posterior contacts. At tension, the adjustive thrust is delivered
posteriorly through the doctor’s torso toward the site of contact
(see Figure 5-165).
To induce extension in the prone or knee-chest positions,
the doctor establishes contacts over the transverse process or
spinous process of the superior vertebra of the dysfunctional
joint. The doctor’s center of gravity is commonly positioned
over the �contacts with the adjustive VEC directed anteriorly
to induce extension (Figure 5-166). In the upper or lower thoracic spine the doctor may face caudally and direct the VEC
slightly inferiorly to assist in the development of tension and
extension.
To induce extension in the supine or standing patient positions, the contacts are typically established over the inferior
vertebral segments. The joint to be adjusted is bent into extension over the top of the posterior contact, and the doctor
T5 T6
T7
T8
Figure 5-165â•… Assisted method, with bilateral
5-165
contacts established on the transverse processes of
T5 to induce flexion at the T5–6 motion segment.
Figure 5-166â•… Bilateral thenar contacts applied over the T7 transverse
processes (center arrow), with the adjustive vector directed posteriorly to
anteriorly. The posterior-to-anterior thrust generates anterior translation
of T7 and extension of T7–8 and T6–7 motion segments.
thrusts �posteriorly, using body weight to induce distraction in
the joints above the contact (Figure 5-167). This adjustment
should also incorporate some long-axis distraction to help
decompress the joint. Straight P-A thrusts may unnecessarily
compress the rib cage.
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211
Adjustive vector
T4
T5
T6
Figure 5-167â•… Bilateral contacts applied to the transverse processes of T6 to induce extension at T5–6. Block indicates
5-167
�
placement of hand under T6 transverse processes and segments below.
overview of rib adjustments
Prone Rib Adjustments
Prone rib adjustments are usually direct short-lever or combined
short- and long-lever methods, incorporating specific but broader
contacts. They are delivered with the patient in a relatively neutral
position; the doctor’s body weight is used in the development of
preadjustive tension. Broader contacts are used so that the thrust
does not focus the force of the adjustment over a small area of the
rib. The rib is more fragile than the vertebral TPs and is therefore
more easily injured.
Sitting Rib Adjustments
Sitting rib adjustments, like sitting thoracic adjustments, afford
the doctor the opportunity to induce rotation or lateral flexion in
the development of preadjustive tension. The adjustive contacts
are established on the rib angle just lateral to the transverse process and are applied as assisted adjustments. The IH contacts the
anterior forearm to assist in the development of appropriate trunk
rotation. At tension, the doctor thrusts to induce distraction at the
costotransverse articulation.
Supine Rib Adjustments
Supine rib adjustments can be very effective in the treatment of
rib dysfunction and should be considered for incorporation in the
management of rib dysfunction. The adjustive impulse in supine
rib techniques is generated by thrusting with the weight of the
doctor’s torso through the patient toward the posterior contact.
The posterior contact is established just medial to the rib angle
with the doctor’s thenar process. The positioning of the patient’s
arms is mainly a matter of doctor discretion and patient comfort.
Gapping Adjustments of the Costotransverse Articulation. The
primary adjustive movement generated at the costotransverse articulation is likely to be one of gapping. This movement is generated
as the rib is distracted from its transverse process articulation. This
movement is most effectively produced by applying a P-A force
against the rib lateral to the transverse process (Figure 5-168).
To induce costotransverse gapping in the prone position, the
doctor establishes a contact over the posterior aspect of the rib angle
Figure 5-168â•… Illustration of gapping at the costotransverse articulation induced by a posterior-to-anterior adjustive force.
just lateral to the transverse process. The adjustive VEC is directed
posteriorly to anteriorly to depress the rib anteriorly and induce
separation at the costotransverse articulation (see Figure 5-192).
To induce gapping in the supine position, the contact is established at the same location, and the doctor accelerates his or her
body weight toward the posterior contact (see Figure 5-187). The
acceleration of the doctor’s body weight through the patient’s
torso is designed to accelerate the patient into the doctor’s posterior contact. The doctor’s posterior contact, which is fixed against
the adjusting table, produces a reactive force anteriorly against the
rib angle, producing gapping at the costotransverse articulation.
Bucket-Handle Rib Adjustments. The side-posture position
is most effective for inducing bucket-handle movements. The
patient lies over a roll to develop preadjustive tension, and a contact is applied in the intercostal space against the superior or inferior aspect of the rib in the midaxillary line. With the �doctor facing
cephalad, the contacted rib is elevated; with the doctor �facing caudal, the rib is depressed (see Figure 5-195).
Thoracic Adjustments
Thoracocervical Adjustments (Box 5-6)
Prone
Thumb/Spinous Push (Figure 5-169)
IND: Restricted rotation or lateral flexion, C6–T3. Rotation, lateral flexion, or combined rotation and lateral flexion malpositions, C6–T3.
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BOX 5-6
Thoracocervical Adjustments
• Prone
• Thumb/spinous push (Figure 5-169)
• Hypothenar/transverse push (Figure 5-170)
• Bilateral/thenar and hypothenar/transverse push
(Figure 5-171)
• Sitting
• Thumb/spinous push (Figure 5-172)
• Side-posture
• Thumb/spinous push (Figure 5-173)
PP: The patient lies prone, with the headpiece lowered below horizontal to produce slight flexion in the thoracocervical spine.
DP: Stand in a low fencer stance on either side of the patient, facing cephaladly. The forward leg approximates the level of the
patient’s head, and your body weight is centered over the midline of the patient.
CP: Distal palmar surface of the thumb. The thumb is partially
abducted and locked, with the fingers resting on the patient’s
trapezius. When standing on the side of adjustive contact, your
caudal hand establishes the contact (Figure 5-169, A). A€fleshy
hypothenar contact may be substituted for the thumb contact
(Figure 5-169, B). When standing on the side opposite the
adjustive contact, the cephalic hand establishes the contact.
SCP: Lateral surface of the spinous process.
IH: Your IH supports the upper cervical spine as the fingers contact the inferior occiput.
VEC: L-M, with slight P-A angulation to maintain the segmental
contact.
P: Lightly establish contacts and develop preadjustive tension.
Deliver an impulse thrust through the contact and the IH. The
impulse generated through the IH is shallow; take care not to
excessively rotate or laterally flex the cervical spine.
A
B
Rotation: Thoracocervical rotational dysfunction may be treated
with assisted or resisted patient positions. When applying
assisted positions, establish the contact on the superior spinous
process on the side of rotational restriction (side of spinous
rotation) (Figure 5-169, A). Slightly laterally flex the neck
toward the side of contact while slightly rotating it away (e.g.,
for right-side contact, induce slight right lateral flexion and
left rotation). Cervical rotation is minimized to ensure neutral
positioning of the thoracocervical spine. The thrust is delivered primarily through the contact hand while the IH produces
only modest cephalic distraction.
When using a resisted method, establish the contact on
the inferior spinous process on the side opposite the rotational restriction (side opposite the spinous rotation) (Figure
5-169,€ B). Develop preadjustive tension by rotating the
patient’s head in the direction of joint restriction and laterally
flex the head toward the side of adjustive contact. At tension,
deliver an impulse counterthrust toward the midline through
both hands.
Lateral flexion: When lateral flexion dysfunction is treated, the
contact is established on the side of lateral flexion restriction (Figure 5-169, C). Preadjustive tension is developed by
laterally flexing the patient’s head toward the side of contact while inducing minimal contralateral rotation. At tension, an impulse thrust is generated medially through the
contact hand while the stabilization hand applies a thrust
cephalically.
Hypothenar/Transverse ↜Push (Combination Move and Modified
Combination Move) (Figure 5-170)
IND: Restricted rotation and/or coupled lateral flexion, C7–T4.
Rotation, lateral flexion, or combined rotation and lateral flexion malpositions, C7–T4.
PP: The patient lies prone, with the headpiece lowered below
horizontal to produce slight flexion in the thoracocervical
spine.
C
Figure 5-169â•… A, Assisted method, with thumb contact applied to the right lateral aspect of the T2 spinous process to induce right
5-169A, B rotation at the T2–3 motion segment. B, Resisted method with a hypothenar contact applied to the right lateral surface of the T3 spinous
process to induce left rotation at the T2–3 joint. C, Hypothenar contact applied to the right lateral surface of the T2 spinous process to induce right lateral flexion in the T2–3 motion segment.
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A
213
B
Figure 5-170â•… A, Assisted position, with hypothenar contact applied to the right T1 transverse process to induce left lateral
5-170A,
B flexion or left rotation the T1-2 motion segment. B, Resisted method, with hypothenar contact applied to the left T2 transverse
process to induce left rotation or right lateral flexion of the T1-2 motion segment.
DP: Stand in a fencer stance, facing cephalad. Your forward leg
approximates the level of the patient’s head, and your upper
body weight should be centered over the contact.
CP: Hypothenar (pisiform) of arched hand. When standing on
the side of adjustive contact (combination move), the caudal hand establishes the vertebral contact (see Figure 5-170,
A). When standing on the side opposite the adjustive contact
(modified combination move), the cephalic hand establishes
the vertebral contact (see Figure 5-170, B).
SCP: Transverse process.
IH: The IH supports the upper cervical spine as the fingers contact the inferior occiput.
VEC: P-A, with same-side contacts (see Figure 5-170, A). P-A and
S-I, with opposite-side contacts (see Figure 5-170, B).
P: Lightly establish the contacts and gently rotate and traction
the patient’s head by producing ipsilateral rotation and contralateral lateral flexion. For example, with a right-side contact, induce left lateral flexion and right rotation of the cervical
spine. At tension, deliver a thrust through the contact and IHs.
The impulse imparted through the IH is shallow; take care not
to excessively rotate or laterally flex the cervical spine. A bodydrop thrust typically assists the impulse.
Rotation: Rotational dysfunction may be treated with assisted
or resisted methods. With assisted patient positions, the doctor typically stands on the side of adjustive contact (see Figure
5-170,€A). Establish the segmental contact on the superior vertebra of the dysfunctional motion segment on the side of posterior body rotation (side opposite the rotational restriction).
Develop preadjustive tension by leaning anteriorly with the
weight of your torso as the IH induces slight lateral flexion
away from the side of contact. Deliver the thrust anteriorly to
distract the joint below the contact.
With resisted methods, the doctor typically stands on the
side opposite the adjustive contact and establishes a contact on
the inferior vertebra on the side opposite the side of posterior
�
vertebral
body rotation (see Figure 5-170, B). Develop preadjustive tension by rotating the patient’s head in the direction of
restriction as you apply counterpressure against the transverse
process contact. At tension, both arms counterthrust to induce
distraction of the articulation superior to the contact.
Lateral flexion: Lateral flexion dysfunction may be treated with
assisted or resisted methods. In both methods, axial rotation
is minimized, and lateral flexion and gliding distraction are
stressed. In the assisted method, the doctor typically stands on
the side of adjustive contact, establishes a contact on the superior vertebra, and thrusts anteriorly and superiorly (see Figure
5-170, A). Prestressing the joint in the direction of desired lateral flexion may assist in the production of lateral flexion. It is
unlikely that this method can induce lateral flexion without
also producing coupled rotation.
In the resisted method, the doctor typically stands on the
side opposite the adjustive contact, establishes a contact on
the inferior vertebra, and thrusts anteriorly and inferiorly in
a direction that opposes the thrust generated with the IH (see
Figure 5-170, B).
Bilateral/Thenar and Hypothenar/Transverse Push (Figure 5-171)
IND: Restricted extension, T1–T4. Flexion malpositions,
T1–T4.
PP: The patient lies prone, with the headpiece lowered below
horizontal for flexion restrictions and neutral for extension
restrictions.
DP: Stand at the head of the table, facing caudad.
CP: Bilateral thenar contacts running parallel to the spine.
(Bilateral knife-edge contacts can also be used.)
SCP: Transverse processes of superior vertebra.
VEC: P-A and S-I (see Figure 5-171).
P: Establish hypothenar contacts with an S-I tissue pull and �develop
joint tension by transferring additional body weight into the contacts. At tension, deliver a thrust through the arms and body.
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| Chiropractic Technique
A
5-171
B
Figure 5-171â•… (A) Bilateral thenar transverse method, applied with an assisted contact and posterior-to-anterior vector to induce
extension. (B)€Bilateral hypothenar (knife edge) method, applied with an assisted contact and P-A and S-I vector to induce extension.
A
B
Figure 5-172â•… A, Assisted method, with a thumb contact applied to the left side of the spinous process of T1 to induce left rotation of T1–2. B, A
thumb contact applied to the left side of the spinous process of T1 to induce left lateral flexion of T1–2.
Sitting
Thumb/Spinous Push (Figure 5-172)
IND: Restricted rotation or lateral flexion, C6–T3. Rotation, lateral flexion, or combined rotation and lateral flexion malpositions, C6–T3.
PP: The patient sits relaxed in a cervical chair.
DP: Stand behind the patient, slightly toward the side of spinous
contact.
CP: Thumb of contact hand, with palm rotated down.
SCP: Lateral surface of the spinous process.
IH: The contralateral hand contacts the top of the patient’s head
while the forearm supports the lateral head and face.
VEC: L-M.
P: Establish the contacts and circumduct the patient’s head toward
the side of spinous contact. At tension, deliver an L-M impulse
thrust through the contact hand.
Rotation: Rotational dysfunction may be treated with either
assisted or resisted methods. When treating rotational restrictions with an assisted method, contact the superior spinous
process on the side of rotational restriction (side opposite
body rotation) and rotate the patient’s head in the direction
of restriction (see Figure 5-172, A). Generate the adjustive
thrust by thrusting toward the midline primarily with the
contact arm.
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
When using a resisted method, contact the inferior spinous
process on the side opposite the rotational restriction (side of
body rotation of superior segment). Rotate the head and segments above in the direction of restriction. At tension, deliver
a thrust by thrusting toward the midline through both arms.
The€greater proportion of the adjustive force is delivered by the
contact arm.
Lateral flexion: When treating lateral flexion dysfunction, establish the contact on the superior vertebra on the side of lateral
flexion restriction. The patient’s neck is laterally flexed in the
direction of restriction. At tension, direct an impulse thrust
toward the midline through the contact arm. The contact
thrust is reinforced by a shallow distractive force delivered with
the IH (see Figure 5-172, B).
Side Posture
Thumb/Spinous Push (Figure 5-173)
IND: Restricted rotation or lateral flexion, C6–T3. Rotation, lateral flexion, or combined rotation and lateral flexion malpositions, C6–T3.
PP: Place the patient in side posture, with the spine in a neutral position and the patient’s head supported in your cephalic
hand.
DP: Stand in front of the patient in a square stance.
CP: Thumb or thenar of caudal hand.
SCP: Lateral surface of the spinous process.
IH: The cephalic hand and forearm cradle the patient’s cervical
spine and head.
VEC: L-M.
P: Stand in front of the patient and lean over to establish the indifferent and segmental contacts. The contacts must be soft and
fleshy or they become uncomfortable to the patient. At tension, deliver an impulse thrust laterally to medially through
the contact hand.
Lateral flexion: When treating lateral flexion dysfunction, establish the contact on the superior vertebra on the side of lateral
flexion restriction. The patient’s neck is laterally flexed in the
direction of restriction. At tension, direct a thrust toward the
A
B
215
midline through the contact arm. The contact thrust is reinforced by a shallow distractive force delivered with the IH (see
Figure 5-173, A and B).
Rotation: Contact the spinous process on the side of deviation
(side of rotational restriction) and rotate the patient’s head
in the direction of restriction. At tension, a thrust is directed
toward the midline. The thrust is reinforced by a shallow
rotational pull through the IH.
Thoracic Adjustments (Box 5-7)
BOX 5-7
Thoracic Adjustments
• Prone
• Bilateral thenar/transverse push (Figure 5-174)
• Bilateral hypothenar/transverse push (crossed bilateral)
(Figure 5-175)
• Unilateral hypothenar/spinous push (Figure 5-176)
• Unilateral hypothenar/transverse push (Figure 5-177)
• Hypothenar spinous crossed thenar/transverse push
(Figure 5-178)
• Knee chest
• Hypothenar/spinous push (Figure 5-179)
• Hypothenar/transverse and bilateral hypothenar/
transverse push (Figure 5-180)
• Supine
• Supine thoracic opposite-side thenar/transverse drop
(Figure€5-181)
• Supine thoracic same-side thenar/transverse drop
(Figure€5-182)
• Supine thoracic pump handle (opposite or same-side)
(Figure 5-183)
• Sitting
• Hypothenar/transverse pull (Figure 5-184)
• Standing
• Thenar/transverse push (Figure 5-185)
• Long-axis distraction (Figure 5-186)
C
Figure 5-173â•… Thumb (A) or thenar (B) contact applied to the right lateral aspect of the C7 spinous process to induce right lateral flexion at the C7-T1
motion segment. C, Thumb contact applied to the right lateral aspect of the T1 spinous process to induce right rotation of the T1–2 motion segment.
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| Chiropractic Technique
A
B
C
5-174A, B, C
Figure 5-174â•… Bilateral thenar contacts applied
to the T8 transverse processes to induce flexion
(A)€and extension (B) of the T8-9 motion segment. C, Alternate method
to create extension, with the doctor facing caudad.
Prone
Bilateral Thenar/Transverse Push (Figure 5-174)
IND: Restricted flexion, extension, lateral flexion, or rotation,
T4–T12. Flexion, extension, lateral flexion, or rotation malpositions, T4–T12.
PP: The patient lies prone. Prestressing spinal joints in the direction
of desired adjustive movement may assist the doctor in inducing
the desired motion. To provide added flexion, a small roll may
be placed under the patient’s chest. To provide added extension,
the thoracic piece may be lowered anteriorly or the patient may
place his or her flexed arms and forearms under the chest.
DP: Stand in a fencer stance on either side of the patient.
CP: Bilateral thenar contacts parallel to the spine, with fingers
fanned and running medially to laterally.
SCP: Transverse processes.
VEC: P-A and I-S to induce flexion, lateral flexion, or rotation
(see Figure 5-174, A). P-A to induce extension or rotation (see
Figure 5-174, B).
P: Establish bilateral thenar contacts and develop joint tension
by transferring additional body weight into the contacts while
tractioning the superficial tissue in the direction of the adjustive
VEC. When using a VEC that is predominantly P-A, the doctor may use either an I-S or S-I tissue pull. The choice depends
on the region adjusted and the doctor’s preference. At tension,
a thrust is delivered through the arms, trunk, and body.
Flexion: To induce flexion, establish the contacts over the superior vertebra and deliver the thrust anteriorly and superiorly
through both contacts (see Figure 5-174, A). Placing a roll
under the level of adjustive contact may increase flexion preadjustive tension.
Extension: To induce extension, establish the contacts over the
superior vertebra and deliver the thrust anteriorly through both
contacts (see Figure 5-174, B and C). To increase preadjustive
tension in extension, the patient may raise his or her torso off
the table by rising up on the forearms or by lowering the thoracolumbar section of an articulating table.
Lateral flexion: To induce lateral flexion, establish bilateral contacts over the superior vertebra but deliver the adjustive thrust
unilaterally. The thrust is delivered anteriorly and superiorly
through the contact established on the side opposite the lateral
flexion restriction. It is unlikely that this method can induce
lateral flexion without inducing coupled rotation.
Rotation: To induce rotation, establish contacts over the superior
or inferior vertebra. With superior vertebral contacts, deliver
the thrust anteriorly on the side of posterior body rotation (side
opposite the rotation restriction). With an inferior vertebra
contact, deliver the thrust anteriorly on the side opposite the
posterior body rotation (side of rotational restriction). Inferior
vertebra contacts (resisted method) are designed to induce gapping of the posterior joints above the site of contact. Inferior
vertebra contacts have not been traditionally used in this manner (see Figure 5-154).
Bilateral Hypothenar/Transverse Push (Crossed Bilateral)
(Figure 5-175)
IND: Restricted flexion, lateral flexion, or rotation, T4–T12.
Extension, lateral flexion, or rotation malpositions, T4–T12.
PP: The patient lies prone. Prestressing spinal joints in the direction of desired adjustive movement may assist the doctor in
inducing the desired motion. To provide added flexion, a small
roll may be placed under the patient’s chest.
DP: Stand in a fencer, modified fencer, or square stance, depending on the restriction treated. Stand on either side of the
patient.
CP: Bilateral hypothenar (pisiform) contacts. A thenar contact
may be substituted for the crossing hypothenar contact
SCP: Transverse processes.
VEC: P-A (see following discussion).
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
A
B
C
Figure 5-175â•… A, Bilateral hypothenar contacts
5-175B
applied to the transverse processes of T6 to induce
flexion at T6–7. B, Crossed bilateral hypothenar contacts applied to the
right T6 transverse process and the left T7 transverse process to induce
left rotation of the T6–7 motion segment. C, Crossed bilateral hypothenar/thenar contacts applied to right and left transverse processes of T6
to induce left lateral flexion of the T6–7 motion segment.
P: Remove superficial tissue slack and establish contacts on the
transverse processes. At tension, deliver a thrust through the
arms, trunk, and body.
Flexion: To induce flexion, stand in a fencer stance, facing cephalad,
and establish contacts on the superior vertebra with your hands
on the edge and your fingers running parallel to the spine. At
tension, deliver a thrust anteriorly and superiorly through both
contacts (see Figure 5-175, A). Placing a roll under the level of
adjustive contact may increase flexion preadjustive tension.
Rotation: When treating rotational dysfunction, stand in a modified
fencer or square stance. Establish bilateral hypothenar contacts;
217
hands are arched and arms cross to contact both sides of the spine.
The caudal hand contacts the superior vertebra on the side of posterior body rotation (side opposite the rotational restriction). The
cephalic hand contacts the contralateral side (Figure 5-175, B).
The hand reaching across the spine may develop a broad stabilizing contact or a contact over the contralateral inferior vertebra. A
thenar contact may be substituted for the hypothenar contact on
the crossed-hand contact.
Develop preadjustive tension by leaning anteriorly into the
contacts and tractioning the hands apart. At tension, deliver a
thrust anteriorly with the caudal hand while the cephalic hand
stabilizes the contralateral structures or counterthrusts anteriorly on the contralateral inferior vertebra (see Figure 5-175,
B).
Lateral flexion: When inducing lateral flexion, establish the segmental contacts bilaterally on the transverse process of the same
vertebra. Deliver the thrust through both hands. One hand
thrusts anteriorly and superiorly while the other thrusts anterior
and inferiorly (see Figure 5-175, C). It is unlikely that segmental lateral flexion can be induced with the patient in a neutral
prone position.32 Prestressing the patient into lateral flexion
may increase the potential for producing lateral flexion.
Unilateral Hypothenar/Spinous Push (Figure 5-176)
IND: Restricted flexion, extension, lateral flexion, or rotation,
T4–T12. Extension, flexion, rotation, or lateral flexion malpositions, T4–T12.
PP: The patient lies prone. Prestressing spinal joints in the direction of desired adjustive movement may assist the doctor in
inducing the desired motion. To provide added flexion, a small
roll may be placed under the patient’s chest. To provide added
extension, the thoracic section of an articulated adjusting table
may be lowered anteriorly.
DP: Stand in a fencer, modified fencer, or square stance, depending on the dysfunction being treated.
CP: Midhypothenar.
SCP: Spinous process.
IH: Your IH supports your contact hand on the dorsal surface,
with the fingers wrapped around the wrist.
VEC: P-A for extension restrictions, P-A and I-S for flexion
restrictions. L-M, S-I, and P-A for rotation or lateral flexion
restrictions.
P: Remove superficial tissue slack and establish a fleshy hypothenar contact against the spinous process. Develop preadjustive
tension by transferring additional body weight into the contact. At tension, deliver a thrust through the arms, trunk, and
body.
Flexion: Stand in a fencer stance, facing cephalad on either side
of the patient. Establish the adjustive contact by sliding the
midhypothenar contact superiorly onto the inferior tip of the
superior spinous process (see Figure 5-176, A), with your center of gravity oriented inferior to the level of adjustive contact.
At tension, thrust anteriorly and superiorly.
Extension: Stand in a fencer stance on either side of the patient.
Establish a midhypothenar contact over the spinous process.
Orient your center of gravity over the dysfunctional joint. At
tension, thrust anteriorly.
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| Chiropractic Technique
A
B
C
Figure 5-176â•… A, Reinforced midline hypothenar
5-176B
contact applied to the inferior aspect of the spinous
process of T7 to induce flexion at T7–T8. B, Hypothenar spinous contact
applied to the right lateral surface of the T3 spinous process to induce right
rotation and right lateral flexion at the T3–4 motion segment. C, Hypothenar
spinous contact applied to the right lateral surface of the T8 spinous process
to induce right rotation and left lateral flexion of the T8–9 motion segment.
Lateral flexion or rotation: Stand in a fencer stance or square
stance on the side of adjustive contact. Establish the adjustive contact by sliding medially onto the lateral surface of the
superior spinous process on the side of rotation or lateral flexion restriction (side of spinous rotation). The contact must
be fleshy or it may be painful to the patient. While developing the contact, apply a slight clockwise or counterclockwise
torquing movement to traction the tissue. This leaves your
fingers oriented at an angle of approximately 45 degrees to the
long axis of the spine (see Figure 5-176, B).
To induce lateral flexion coupled with same-side rotation,
the cephalic hand is used as the contact. Stand in a square
stance or modified fencer stance and face caudally (see Figure
5-176, B). This adjustment is commonly applied in the treatment of coupled restrictions in rotation and lateral flexion to
the same side (PRS or PLS listings)
To induce lateral flexion coupled with opposite-side rotation (PRI or PLI listings), the caudal hand establishes the contact and you stand in a square stance or modified fencer stance,
facing cephalically (see Figure 5-176, C). At tension, deliver an
�adjustive thrust anteromedially and superiorly. Spinous contact methods are not commonly used for treating oppositeside restrictions in rotation and lateral flexion. It is unlikely
that prone spinous contacts can induce segmental rotation or
lateral flexion with the patient in a neutral prone position.32
Prestressing the patient into lateral flexion may increase the
potential for the desired motions.
Unilateral Hypothenar/Transverse Push (Figure 5-177)
IND: Restricted rotation or lateral flexion, T4–T12. Rotation or
lateral flexion malpositions, T4–T12.
PP: The patient lies prone.
DP: Stand in a fencer stance or square stance on the side of adjustive contact.
CP: Hypothenar (pisiform) of caudal hand, with hand arched and
fingers running parallel to the spine.
SCP: Transverse process.
IH: Your IH supports your contact hand on the dorsal surface,
with the fingers wrapped around the wrist.
VEC: P-A, coupled with an I-S or S-I VEC, depending on the
dysfunction treated and the vertebra contacted.
P: Remove superficial tissue slack and establish transverse process contacts. Develop preadjustive tension by transferring
�additional body weight into the contacts. At tension, deliver a
thrust through the arms, trunk, and body.
Rotation: When treating rotational dysfunction, you may establish
contacts on the superior or inferior vertebra of the dysfunctional
motion segment. When contacting the superior vertebra, establish the contact on the side opposite the rotational restriction (side
of posterior body rotation) (see Figure 5-177, A). When contacting the inferior vertebra, establish the contact on the side of
rotational restriction (side opposite posterior body rotation) (see
Figure 5-177, C). The inferior vertebral �contact (resisted method)
is applied to induce more tension and �gapping in the joint superior to the contact. The method is not commonly applied.
Lateral flexion: When treating lateral flexion dysfunction, establish the contact over the superior vertebra. When contacting
the transverse process on the side opposite the lateral flexion restriction, stand in a fencer stance, facing cephalically.
Establish the contact with the caudal hand and deliver the
adjustive thrust anteriorly and superiorly (see Figure 5-177,
A). When contacting the side of lateral flexion restriction,
stand in a square or fencer stance and establish the contact
with the cephalic hand. Deliver the thrust anteriorly and inferiorly (see Figure 5-177, B). It is unlikely that �segmental �lateral
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
219
A
A
B
B
C
Figure 5-177â•… A, Assisted hypothenar contact
5-177A
applied to the right T5 transverse process to
induce left rotation or left lateral flexion at the T5–6 motion segment.
B,€Assisted hypothenar contact applied to the right transverse process of
T5 to induce right lateral flexion at T5–6 motion segment. C, Resisted
hypothenar contact applied to the right transverse process of T5 to
induce right rotation and gapping in the right T4–5 articulation.
flexion can be induced with the patient in a neutral prone position.32 Prestressing the patient into lateral flexion may increase
the potential for producing lateral flexion.
Hypothenar Spinous Crossed Thenar/Transverse Push (Figure
5-178)
IND: Restricted rotation and or coupled lateral flexion, T4–T12.
Rotation or coupled lateral flexion malpositions, T4–T12.
PP: The patient lies prone.
DP: Stand in a modified fencer stance or square stance on side of
spinous contact.
Figure 5-178â•… Hypothenar (A) or thumb
5-178
(B)€contact applied to the right lateral surface of the
T4 spinous process and a thenar contact applied to the left T4 transverse process to induce right rotation or right lateral flexion at the T4–5
motion segment.
CP: Hypothenar (pisiform) (see Figure 5-178, A) or thumb (see
Figure 5-178, B) of the cephalic hand and thenar of the caudal hand.
SCP: Lateral surface of the spinous process and transverse process
of the corresponding vertebra.
VEC: P-A, L-M, and S-I, with hand contacting the spinous process. P-A and I-S, with transverse process contact.
P: Remove superficial tissue slack by sliding the thumb or hypothenar against the lateral surface of the spinous process while sliding the thenar superiorly onto the ipsilateral transverse �process.
�Develop preadjustive tension by transferring additional body
weight into the contacts. At tension, deliver a thrust through
the arms and body. It is unlikely that segmental lateral flexion
can be induced with the patient in a neutral prone position.32
Prestressing the patient into lateral flexion may increase the
potential for producing lateral flexion.
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| Chiropractic Technique
Knee-Chest
Hypothenar/Spinous Push (Figure 5-179)
IND: Restricted extension, lateral flexion, or rotation, T4–T12.
Flexion, rotation, or lateral flexion malpositions, T4–T12.
PP: Position the patient in the knee-chest position, with the chest
support placed so that the patient’s thoracic spine is level with
or slightly lower than the lumbar spine. The patient’s femurs
should be angled between 95 and 110 degrees.
DP: Stand at the side of the table in a square stance, typically on
the side of the contact. You may also stand in a fencer stance,
facing caudally.
CP: Hypothenar.
SCP: Lateral surface of the spinous process.
IH: Your IH supports your contact hand on the dorsal surface,
with the fingers wrapped around the wrist.
Figure 5-179â•… Hypothenar contact applied to the left lateral surface
of the T8 spinous process to induce extension, left rotation, or left lateral
flexion at the T8-9 motion segment, using the knee-chest position.
A
VEC: P-A for extension restriction or flexion malposition. L-M, S-I,
and P-A for rotation or lateral flexion restrictions or malpositions.
P: The IH first raises the patient’s abdomen to make the spinous processes more prominent and available for establishing the contacts.
Instruct the patient to allow the torso to drop, and at tension,
deliver an impulse thrust. Knee-chest tables provide their greatest
advantage in assisting the doctor in the application of inducing
spinal extension. The potential to induce lateral flexion may be
improved by prestressing the patient in the direction of desired
lateral flexion. The patient is vulnerable to hyperextension in this
position, so the thrust must be shallow and nonrecoiling.
Hypothenar/Transverse and Bilateral Hypothenar/Transverse
Push (Figure 5-180)
IND: Restricted extension, lateral flexion, or rotation, T4–T12.
Flexion, rotation, or lateral flexion malpositions, T4–T12.
PP: Position the patient in the knee-chest position, with the chest
support placed so that the patient’s thoracic spine is level with
or slightly lower than the lumbar spine. The patient’s femurs
should be angled between 95 and 110 degrees.
DP: Stand at the side of the table in a square stance, when using unilateral contact. You may also stand in a fencer stance, facing caudally.
CP: Hypothenar (pisiform).
SCP: Transverse process.
IH: With a unilateral contact, the IH supports the contact hand
on the dorsal surface, with the fingers wrapped around the
wrist. With bilateral contacts, the IH is placed on the opposite
side to stabilize or impart an assisting impulse.
VEC: P-A.
P: The IH first raises the patient’s abdomen to make the transverse process more prominent and available for establishing
the contacts. Instruct the patient to allow the torso to drop,
and at tension, deliver an impulse thrust. The patient is vulnerable to hyperextension in this position, so the thrust must
be shallow and nonrecoiling. If the IH delivers an assisting thrust, it is directed posteriorly to anteriorly. Knee-chest
tables provide their greatest advantage in �assisting the doctor
B
Figure 5-180â•… A, Unilateral hypothenar contact applied to the right T5 transverse process to induce left rotation and or right lateral flexion at the
T5–6 motion segment. B, Bilateral hypothenar contacts applied to the T5 transverse processes to induce extension at the T5–6 motion segment.
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
in the �application of inducing spinal extension. The potential
to induce lateral flexion may be improved by prestressing the
patient in the direction of desired lateral flexion.
Supine
Opposite-Side Thenar/Transverse Drop (Figure 5-181)
IND: Restricted flexion, extension, rotation, or lateral flexion,
T3–T12. Flexion, extension, rotation, or lateral flexion malpositions, T3–T12.
PP: The patient sits or lies supine, with arms crossed and hands
grasping shoulders.
DP: Stand in a modified fencer stance and reach around the
patient to establish the posterior contact.
221
CP: The cupped hand, clenched fist, or index or thenar of the
contact hand (see Figure 5-147).
SCP: Bilateral transverse process, unilateral transverse process,
depending on the dysfunction being treated.
IH: Your IH contacts the patient’s crossed arms or cradles the
patient’s neck and upper back (see Figure 5-181, A and B).
VEC: A-P and I-S through the doctor’s torso. A-P for extension or
rotational dysfunction.
P: When starting in the supine position, first roll the patient
toward you to place the posterior spinal contact (see Figure
5-181, A). Slide superiorly to establish a superior vertebral
contact and inferiorly to establish an inferior vertebral contact.
After the spinal contact is established, return the patient to the
A
B
C
D
Figure 5-181â•… Supine thoracic adjustment, using an opposite-side contact, with the patient in a crossed-arm position.
5-181C, D
A, Starting in the supine position. B, Starting in the seated position. C, Assisted method, using a cradling support and a
clenched fist applied to the transverse process of T7 to induce flexion at the T7–8 motion segment (small arrow indicates direction of tissue pull).
D, Resisted method, using a crossed-shoulder support and a clenched fist applied to the transverse process of T8 to induce flexion at the T7–8
motion segment (small arrow indicates direction of tissue pull).
(Continued)
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| Chiropractic Technique
E
F
G
Figure 5-181–Cont’dâ•… E, Clenched-fist contact applied to the T8 transverse process to induce extension at the T7–8
motion segment. F, Assisted thenar contact established on the right T3 transverse process to induce left rotation of the right
T3–4 articulation. G, Resisted thenar contact applied to the right T4 transverse process to induce right rotation and gapping of the right T3–4
articulation.
5-181E, G
supine position and initiate the IH contacts (see Figure 5-181,
C to E). During this process, it is important that the patient
is rolled onto the contact hand with minimal pressure. Undue
pressure exerted against the anterior contacts can lead to painful compression against your posterior contact.
Develop preadjustive tension by adding progressive compression and traction through your trunk and anterior contacts. At tension, deliver a short-amplitude, moderate-velocity
body-drop thrust, generated primarily through your trunk and
lower extremities. When applying supine adjustive techniques,
it is important to avoid straight compression to the trunk and
rib cage. This is accomplished by applying slight headward
traction during the development of tension.
Supine thoracic adjustments are also commonly started
with the patient in a sitting position. This is particularly helpful when adjusting the lower thoracic spine, when adjusting
large patients, or when rolling the patient onto the contact is
too painful (Figure 5-181, B).
Flexion: When treating flexion restrictions (extension malpositions), the patient is maintained in a position of segmental flexion (see Figure 5-181, C and D). Place the adjustive contacts
bilaterally on the transverse processes or in the midline, against
the spinous process. Establish the transverse contacts with your
cupped hand or clenched fist.
When using an assisted method, establish the contact on the
transverse process of the superior vertebra of the dysfunctional
motion segment (see Figure 5-181, C). At tension, deliver the
thrust posteriorly and superiorly through the trunk, legs, and
posterior contact.
When using a resisted method, establish the contact on the
transverse process of the inferior vertebra (see Figure 5-181,
D). Apply downward counterpressure through the contact to
oppose the adjustive thrust, which is directed posteriorly and
superiorly through the trunk and legs.
Extension: When treating extension restrictions (flexion malpositions), establish the contact bilaterally on the transverse
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
processes of the inferior vertebra of the dysfunctional motion
segment. Develop preadjustive tension by inducing segmental
extension and deliver the adjustive thrust posteriorly (Figure
5-181, E).
Rotation: To produce rotation you may establish unilateral thenar contacts on either the superior or inferior vertebra of the
involved motion segment. When using a superior vertebral contact (assisted method), establish the contact on the transverse
process on the side opposite the rotation restriction (side of
posterior body rotation). Maintain the patient in a flexed position and direct the thrust posteriorly (see Figure 5-181, F).
When using an inferior vertebral contact (resisted method),
establish the contact on the transverse side of the rotational restriction (side opposite posterior body rotation). For example, when
treating a right rotation restriction at T3–4 (left body rotation),
the contact would be established on the right T4 transverse process. During the development of preadjustive tension, the patient
is rolled farther toward the side of the posterior contact (see Figure
5-181, G). The adjustive thrust is directed posteriorly. The inferior
vertebral contact (right T4 contact) is applied to induce gapping in
the facet joint ipsilateral and superior to the contact.
Lateral flexion: Lateral flexion dysfunction is typically treated by
establishing unilateral contacts on the side opposite the lateral
flexion restriction. When using assisted patient positions, contact the superior vertebra, induce flexion and lateral flexion
away from the side of contact and thrust posteriorly through
the trunk and legs.
When using resisted methods, contact the inferior vertebra,
laterally flex the patient away, and apply downward counterpressure with the contact to oppose the adjustive thrust. This
method may be applied to treat combined restrictions in rotation and opposite-side lateral flexion.
Same-Side Thenar/Transverse Drop, Crossed Arm (Figure 5-182)
IND: Restricted flexion, extension, rotation, or lateral flexion,
T3–T12. Flexion, extension, rotation, or lateral flexion malpositions, T3–T12.
223
PP: Ask the patient to sit or lie supine, with arms crossed and
hands grasping shoulders.
DP: Stand in a fencer stance on the side of adjustive contact.
CP: The cupped hand, clenched fist, or thenar of the contact hand.
SCP: Bilateral transverse process, or unilateral transverse process,
depending on the restriction being treated.
IH: Use your IH to contact the patient’s crossed arms or cradle the
patient’s neck and upper back.
VEC: A-P through the doctor’s torso.
P: Stand on the side of the established contact and instruct the
patient to cross his or her arms. Roll the patient away from you
and establish the posterior contact. Then roll the patient back
into position and contact the patient’s crossed arms or cradle
the patient’s neck and shoulders (see Figure 5-182). Progressive
compression to remove soft tissue slack is followed by a moderate-velocity, �short-amplitude body-drop thrust.
The specific considerations for flexion, extension, and rotational restrictions are the same as previously mentioned in the
adjustments described in Figure 5-181, C to G. Other than
�personal preference, this method is commonly applied in the
treatment of larger patients or if less contact is desired between
the doctor and patient.
Thenar/Transverse Drop, Pump Handle (Opposite or SameSide) (Figure 5-183)
IND: Restricted flexion, rotation, or lateral flexion, T3–T12. Flexion,
extension, rotation, or lateral flexion malpositions, T3–T12.
PP: The patient may begin in either the sitting or supine position, with elbows flexed and fingers interlocked or overlapping
behind neck.
DP: Stand in a fencer stance on either side of the patient.
CP: The cupped hand, clenched first, or thenar of your contact hand.
SCP: Bilateral transverse process, or unilateral transverse process,
depending on the dysfunction treated.
IH: Either cradle the patient’s neck and upper back with the IH
and arm or support the patient by leaning across the patient’s
�forearm with the forearm and upper abdomen (see Figure 5-183,
A and B [opposite-side method]; C and D [same-side method]).
VEC: A-P and I-S to produce flexion or lateral flexion. A-P for
extension or rotation.
P: Stand on either side of the patient and establish the posterior
contacts. Your IH and forearm contact the patient’s forearms or
reach around to cradle the patient’s neck and upper back. The
development of preadjustive tension and the delivery of the
adjustive thrust are identical to those previously described.
The specific considerations for flexion, and rotational
dysfunction are the same as previously mentioned in supine
adjustments. The pump handle position is especially helpful
in inducing flexed patient postures and is not frequently used
when inducing extension.
Sitting
Figure 5-182â•… Supine thoracic adjustment,
5-182A, B using a crossed-arm patient position and a same-side
contact applied to a midthoracic �segment to induce extension.
Hypothenar/Transverse Pull (Figure 5-184)
IND: Restricted rotation or coupled lateral flexion, T5–T12.
Rotation or lateral flexion malpositions, T5–T12.
PP: The patient sits with legs straddling the adjusting bench. The
patient’s arms are crossed with the hands grasping the shoulders.
A
B
C
D
Figure 5-183â•… Supine thoracic adjustments, using patient pump-handle position to assist in the development of flexion.
5-183B
A, Opposite-side method, with the doctor assisting the production of flexion with a forearm contact across the patient’s flexed forearms. B, Opposite-side method, with doctor cradling the patient. C, Same-side method, with cradling support and a pump-handle position. D, Sameside method, with the doctor assisting the production
�
of flexion with a forearm contact across the patient’s flexed forearms.
A
B
Figure 5-184â•… A, Sitting assisted hypothenar transverse contact applied to the left T6 transverse process to induce right rotation
5-184A
and right lateral flexion of the T6–7 motion segment. B, Sitting assisted hypothenar spinous contact applied to the left lateral surface
of the T6 spinous to induce left rotation and right lateral flexion of the T6–7 motion segment.
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
DP: Sit or stand behind the patient.
CP: Hypothenar or thenar of hand corresponding to the side of
contact.
SCP: Transverse or spinous process of superior vertebra.
IH: Your IH and arm reach around the patient to contact the opposing forearm. The IH is active in producing adjustive force
VEC: Pulling rotatory force generated by doctor’s anterior arm
contact and torso.
P: Ask the patient to sit and cross his or her arms. Position yourself behind the patient in either a standing or seated position
(see Figure 5-184). Preadjustive tension is typically developed
by flexing, laterally flexing, and rotating the patient in the
direction of joint restriction (assisted method). Once tension is
established, deliver an impulse thrust by inducing a pulling and
twisting thrust generated through your indifferent arm trunk
and posterior contacts. The direction of induced lateral flexion
and the point of adjustive contact depend on the dysfunction
being treated.
Rotation: When treating rotational dysfunction, you may establish contacts on the spinous process or transverse process. When
using a transverse process contact, establish the contact on the
superior vertebra on the side opposite the rotation restriction
(side of posterior body rotation) (see Figure 5-184, A). To use
a spinous process contact, slide medially and establish a fleshy
mid-hypothenar contact on the lateral surface of the spinous
process on the side of rotational restriction (side of spinous
rotation) (see Figure 5-184, B). Laterally flexing the patient
away from the side of contact is commonly incorporated to
increase distraction in the joint on the side of contact.
Lateral flexion: Pure lateral flexion cannot be effectively produced with sitting thoracic adjusting methods; some degree of
rotation is a product of sitting thoracic methods. Patients who
cannot tolerate moderate rotation of the spine are not good
candidates for sitting thoracic methods.
To treat lateral flexion dysfunction, contact the transverse
process of the superior vertebra on the side opposite the lateral
flexion restriction (Figure 5-184, A). Develop preadjustive tension by flexing and laterally flexing the patient away from the
side of contact.
Combined rotation and lateral flexion: Sitting thoracic adjustments can also be applied to treat combined restrictions in rotation and lateral flexion. Transverse process contacts are more
commonly applied with restrictions in rotation and same-side
lateral flexion, and spinous process contacts may be more effective in treating restrictions in rotation and opposite-side lateral
flexion. Figure 5-184, A, demonstrates treatment of a rotation
and same-side lateral flexion restriction, and Figure 5-184, B,
demonstrates rotation and opposite-side lateral flexion.
Standing
Thenar/Transverse Push (Figure 5-185)
IND: Restricted flexion, extension, rotation, or lateral flexion, T3–T12. Flexion, extension, rotation, or lateral flexion
Â�malpositions, T3–T12.
PP: The patient stands, leaning against a wall, with feet shoulderwidth apart. The arms are crossed, with the hands grasping the
shoulders.
A
225
B
Figure 5-185â•… Standing thoracic adjustment for a
5-185B
midthoracic segment. A, Against a wall to induce flexion. B, Against a wall to induce extension.
DP: Stand on either side of the patient in a fencer stance, with
your medial leg posterior and body angled about 45 degrees
to the patient.
CP: Your cupped hand or fist or the open palm of your outside hand
reaches behind the patient to contact the patient posteriorly. Your
hand must be cushioned from the wall by using a padded wall
board or placing a pad between your hand and the wall.
SCP: Transverse or spinous process of involved vertebra.
IH: Your IH contacts the patient’s crossed arms.
VEC: A-P and I-S
P: Stand to the side of adjustive contact, rotate the patient away,
and establish the posterior contact. Develop preadjustive
�tension by leaning into the patient while applying vertical traction. As tension is developed, it is important to produce some
long-axis traction by pushing cephalically through your legs
and arms. At tension, deliver an impulse thrust through your
trunk and lower extremities.
Extension: With extension restrictions (flexion malpositions),
contact the inferior vertebra, extend the motion segment, and
deliver the thrust posteriorly (see Figure 5-185, B).
Flexion: When treating flexion restrictions (extension malpositions), the superior vertebra of the dysfunctional motion
�segment is typically contacted. Maintain the patient in a position of flexion and deliver the thrust posteriorly and superiorly
�(see Figure 5-185, A). This is the most difficult dysfunction to
treat with standing thoracic methods because flexed postures
roll the patient’s spine away from the doctor’s posterior contact.
This can be minimized, to some degree, by having the patient
push his or her buttocks away from the wall.
Rotation: When treating rotation dysfunction, adjustive contacts
may be established on the superior or inferior vertebra of the
dysfunctional motion segment. When using a superior verte-
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| Chiropractic Technique
bral contact (assisted method), establish the contact on the side
opposite the rotation restriction (side of posterior body rotation). Position the patient in slight flexion and deliver a thrust
posteriorly and superiorly.
When using an inferior vertebra contact (resisted method),
establish the contact on the side of rotational restriction (side
opposite the posterior body rotation) and deliver a thrust posteriorly. This adjustment may also be used for rib dysfunction
by moving the contact lateral to the angle of the involved rib.
Lateral flexion: Lateral flexion dysfunction is typically treated by
establishing unilateral contacts on the side opposite the lateral
flexion restriction. When using assisted patient positions, contact the superior vertebra and induce flexion and lateral flexion
away from the side of contact. At tension, thrust posteriorly
and superiorly through the trunk and legs toward the posterior
contact.
When using resisted methods, contact the inferior vertebra
and laterally flex the patient away from the side of contact. Apply
inferior counterpressure with the posterior contact to oppose the
anterior and superiorly directed adjustive thrust. This method
may be applied to treat combined rotation and opposite-side lateral flexion dysfunction. It is unlikely that this method can induce
lateral flexion without the production of coupled rotation.
Thoracic Long-Axis Distraction (Figure 5-186)
IND: Restricted flexion and long-axis distraction, T3–T12.
Extension malpositions, T3–T12.
PP: The patient stands with feet at least 10 inches apart (more
if the patient is taller than the doctor), with hands interlaced
behind the neck and elbows together or arms crossed over the
chest.
DP: Stand behind the patient in a fencer stance, placing your
Â�forward leg between the patient’s legs. Your anterior chest may
be padded with a sternal roll or small pillow.
CP: A true segmental contact is not established on the back, but
the sternal angle of the doctor is placed over the region to be
distracted.
SCP: Over the spinous processes of the dysfunctional region.
VEC: A-P and I-S.
P: Grasp the patient’s forearms, stressing the patient’s thoracic
spine into slight flexion. At tension, pull posteriorly and superiorly through the patient’s arms.
This procedure is applied to develop regional distraction,
although a sternal block can be used to make the contact more
specific. It can be applied as a thrust or nonthrust mobilization
procedure. The thrust is gentle and shallow and generated by
the doctor pulling posteriorly and superiorly through the contacts on the patient’s elbows.
Rib Adjustments (Box 5-8)
BOX 5-8
Rib Adjustments
• Supine
• Thenar/costal drop (Figure 5-187)
• Index/costal push (Figure 5-188)
• Prone
• Hypothenar/costal push (Figure 5-189)
• Modified hypothenar (thenar)/costal push
(Figure 5-190)
• Index/costal push (Figure 5-191)
• Hypothenar costal/push (Figure 5-192)
• Ilial hypothenar/costal push (Figure 5-193)
• Covered-thumb/costal push (Figure 5-194)
• Side posture
• Web/costal push (Figure 5-195)
• Sitting
• Index/costal push (Figure 5-196)
• Hypothenar (thenar)/costal push (Figure 5-197)
Costosternal Adjustments
• Supine covered thumb/costosternal push
(Figure 5-198)
• Sitting hypothenar/costosternal pull (Figure 5-199)
Supine
Figure 5-186â•… Standing thoracic adjustment for a midthoracic segment,
with the doctor standing behind to induce flexion and long-axis distraction.
Thenar/Costal Drop (Figure 5-187)
IND: Rib dysfunction, R2–R12.
PP: The patient lies supine, with arms crossed and the hands
grasping the shoulders. Patient arm placement is at the Â�doctor’s
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A
227
B
C
D
Figure 5-187â•… Supine rib adjustment, using a thenar contact over the right third rib starting in the supine position (A) and an
5-187A, B
anterior-to-posterior thrust through the doctor’s torso to induce gapping in the right costotransverse articulation (B). C, Thenar
contact applied over the inferior margin of€the right eighth rib, starting in the seated position. D, Anterior-to-posterior thrust through the doctor’s torso
to induce gapping in the right eighth costotransverse articulation.
�
discretion.
When treating lower rib fixations, the patient typically begins in the seated position.
DP: Stand in a modified fencer stance on either side of the
patient.
CP: Thenar eminence.
SCP: Just medial to the rib angle.
IH: Your IH contacts the patient’s crossed arms or cradles the
patient’s neck and upper back.
VEC: A-P.
P: Stand in a low fencer stance on either side of the patient. Access
the contact by rolling the patient toward you or placing him or
her in a sitting position (see Figure 5-187).
At tension, direct a moderate-velocity thrust toward the posterior contact established on the rib. Acceleration of the doctor’s
body weight toward the posterior contact accelerates the patient’s
torso toward the doctor’s posterior contact, which in turn exerts a
P-A force against the rib contact. The reactive P-A force generated
against the rib is designed to accelerate the rib forward and induce
gapping in the costotransverse joint.
In the treatment of lower rib dysfunction, the patient is typically
started in the sitting position (see Figure 5-187, B). The patient is
maintained in some degree of thoracolumbar flexion, and the contact hand is held in a more vertical (bridged) contact to establish
tension in the lower thoracic spine (see Figure 5-187, D).
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| Chiropractic Technique
Index/Costal Push (Figure 5-188)
IND: Dysfunction of the first rib.
PP: The patient lies supine.
DP: Stand at the head of the table, facing caudad.
CP: Index contact of the hand corresponding to the side of contact.
SCP: Angle of first rib.
IH: Your IH cups the patient’s ear with the palm while the index
and middle fingers support the upper cervical spine
VEC: S-I and L-M.
P: To establish the contact, the IH raises the patient’s head to
about a 45-degree angle and then extends the head backward
over the index contact on the first rib. The head is then rotated
Figure 5-188â•… Index contact established over the
5-188
superior aspect of the angle of the left first rib to distract the left T1 costotransverse articulation.
A
5-189B
about 20 degrees away from the contact and slightly laterally
flexed over the contact. At tension, an impulse thrust is delivered superiorly to inferiorly and laterally to medially.
Prone Upper
Hypothenar/Costal Push (Figure 5-189)
IND: Rib dysfunction, R1–R4.
PP: The patient lies prone, with the headpiece lowered below horizontal to produce slight flexion in the thoracocervical spine.
(The patient’s head rests on the anterolateral cheek.)
DP: Stand in a fencer stance on either side of the patient, facing
cephalad. Your superior leg approximates the level of the patient’s
head and your upper body weight is centered over the contact.
CP: Hypothenar of arched hand. When standing on the same
side of adjustive contact (combination move), the hypothenar
of your caudal hand establishes the contact (see Figure 5-189,
A). When standing on the side opposite the adjustive contact
(modified combination move), the hypothenar of your cephalic
hand establishes the contact (see Figure 5-189, B).
SCP: Rib angle.
IH: The IH supports the upper cervical spine as the fingers contact the inferior occiput.
VEC: P-A.
P: Place the patient in the prone position and establish the adjustive contacts. Develop preadjustive tension by transferring body
weight into the contact while rotating the patient’s head toward
and laterally flexing it away from the contact. At tension, deliver
an impulse thrust through the contact and indifferent arms. The
impulse delivered through the contact hand is typically assisted
by a body-drop thrust. The impulse imparted through the IH
B
Figure 5-189â•… Hypothenar contact established on the superior margin of the angle of the left first rib applied to distract the left
costotransverse articulation. A, Doctor stands on the same side as the contact. B, Doctor stands on the opposite side of the contact.
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229
Figure 5-190â•… Hypothenar contact established over the second rib to
induce distraction of the left second costotransverse articulation.
Figure 5-191â•… Index contact established over the superior angle of the
is shallow, and care should be taken not to excessively rotate or
laterally flex the cervical spine. To maximize distractive tension
in the soft tissues or intercostal tissues superior to the contact,
apply caudal pressure against the rib angle.
SCP: Posterior superior angle of the first rib.
IH: Your IH cups the patient’s contralateral inferior occiput and
lateral skull.
VEC: S-I, L-M, and P-A.
P: After establishing the contacts, laterally flex the patient’s head
toward the contact while rotating it away (e.g., with the contact established on the patient’s left first rib, the patient’s head
is left laterally flexed and right rotated). At tension, deliver an
impulse thrust through the contact hand while a simultaneous
counterdistraction force is delivered through the IH.
Modified Hypothenar (Thenar)/Costal Push (Figure 5-190)
IND: Rib dysfunction, R1–R2.
PP: The patient lies prone, with the headpiece lowered below
�horizontal to produce slight flexion in the thoracocervical spine.
(The patient’s head rests on the anterolateral aspect of the cheek.)
DP: Stand in a fencer stance at the head of the adjustive bench,
facing caudad.
CP: Hypothenar of hand corresponding to the side of contact.
The arm is straight, with the elbow locked.
SCP: Posterior superior angle of the first or second rib.
IH: Your IH cups the patient’s ipsilateral ear while the fingers rest
against the lateral face.
VEC: P-A and S-I.
P: After establishing the contacts, the patient’s head is laterally flexed
away and rotated toward the contact. At tension, an impulse
thrust is delivered through the contact hand while a �simultaneous
counterdistraction force is delivered through the IH. The �adjustive
force is delivered primarily with a body-drop thrust.
Index/Costal Push (Figure 5-191)
IND: Rib dysfunction, R1.
PP: The patient lies prone. (The patient’s head rests on the anterolateral aspect of the cheek.)
DP: Stand in a low fencer stance, facing cephalad, on the side of
rib dysfunction, slightly headward of the adjustive contact.
CP: Index finger of hand corresponding to the side of contact.
The wrist is straight and locked, with arm approximately 45
degrees to vertical plane.
left first rib to induce distraction of the left costotransverse articulation.
Prone
Hypothenar/Costal Push (Figure 5-192)
IND: Rib dysfunction, R3–R10.
PP: The patient lies prone, ideally on a table with a brachial cutout to induce scapular abduction.
DP: The doctor stands in a fencer stance when using unilateral
contacts and in a square stance when using bilateral contacts.
CP: Hypothenar of the cephalic hand in the upper thoracic spine
and the caudal hand in the lower thoracic spine.
SCP: Rib angle.
IH: Your IH supports the contact hand or develops a broad stabilizing contact on the contralateral rib cage.
VEC: P-A.
P: Place the patient in the prone position and establish the adjustive contacts. Develop preadjustive tension by transferring body
weight into the contact. At tension, deliver an impulse thrust
through the contact arm, assisted by a body-drop thrust.
When treating upper rib dysfunction thrust anteriorly
and inferiorly (see Figure 5-192, A). When treating lower
rib dysfunction thrust anteriorly and superiorly (see Figure
5-192, B).
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| Chiropractic Technique
B
A
Figure 5-192â•… A, Hypothenar contact applied to the superior margin of the right sixth rib angle to induce gapping of the right
5-192A, B sixth costotransverse articulation. Crossed contact applies gentle countersupport without imparting a thrust. B, Hypothenar �contact
applied to the inferior margin of the right fourth rib angle to induce gapping of the right fourth costotransverse articulation.
A
5-193
B
Figure 5-193â•… Hypothenar contact applied to the inferior margin of the left ninth rib angle to induce distraction of the left
ninth costotransverse articulation. A, Doctor in a square stance. B, Doctor in modified square stance, facing caudally.
Ilial Hypothenar/Costal Push (Figure 5-193)
IND: Rib dysfunction, R7–R12.
PP: The patient lies prone. To provide added flexion, a small roll
may be placed under the patient’s upper abdomen.
DP: Stand in a square stance (see Figure 5-193, A) or a modified
fencer stance (see Figure 5-193, B) on the side opposite the
adjustive contact.
CP: Hypothenar of cephalic hand.
SCP: Rib angle.
IH: The fingers of your inferior hand reach around to grasp the
anterior ilium (anterosuperior iliac spine [ASIS]) on the side of
adjustive contact.
VEC: P-A, I-S, and L-M.
P: Establish contacts on the rib angle and anterior ilium and
induce preadjustive tension by lifting and tractioning inferi-
orly against the ilium as the weight of your trunk is transferred
anteriorly and superiorly against the contact. The counterdistractive tension induced through the ilium is not marked, and
the patient’s pelvis should not be rotated off the table more
than 1 to 2 inches. Deliver the thrust with an impulse and
body-drop thrust through the contact hand. A thumb-thenar
contact can be placed in the intercostal space laterally to influence bucket-handle movements.
Covered-Thumb/Costal Push (Figure 5-194)
IND: Rib dysfunction, R3–R12.
PP: The patient lies in the prone position.
DP: Stand on side opposite of contact, facing cephalad for I-S
VEC or caudad for S-I VEC.
CP: The cephalad hand’s thumb-thenar contact follows the rib
contour.
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231
Figure 5-195â•… Web contact applied to the
5-195
�
inferior margin of the right seventh rib in the midaxillary line to induce separation in the intercostal space between the seventh and eighth ribs.
Figure 5-194â•… Covered-thumb contact applied
5-194
to the left fifth rib angle to induce distraction of the
left fifth costotransverse articulation.
SCP: Angle of the rib just lateral to the transverse process.
IH: Place the caudad hand’s pisiform-hypothenar contact over contact
hand’s thumbnail, with the fingers wrapped around the wrist.
VEC: P-A and either S-I or I-S.
P: Lean in with your body weight to establish joint and deliver a
straight-arm body-drop thrust.
PP: The patient sits relaxed in a cervical chair.
DP: Stand behind the patient, toward the side of rib dysfunction.
CP: Index finger of the hand corresponding to the side of dysfunction. The wrist is locked, with the arm angled approximately 45 degrees to the horizontal plane.
SCP: Posterior superior angle of the first rib.
IH: The IH grips the top of the patient’s head while the forearm
rests against the patient’s contralateral skull.
VEC: S-I, L-M, and P-A.
Side-Posture
Web/Costal Push (Figure 5-195)
IND: Rib dysfunction, R2–R10 (bucket-handle dysfunction or
intercostal distraction).
PP: The patient lies with the dysfunctional side up and arm abducted
over the head. A roll may be used to induce lateral flexion.
DP: Stand behind the patient in a fencer stance, inferior to the
contact.
CP: Web contact of the outside hand.
SCP: Inferior margin of the superior rib at the midaxillary line.
IH: The IH supports the contact hand on the dorsal surface, with
the fingers wrapped around the wrist.
VEC: I-S and L-M.
P: Establish the adjustive contact by sliding the web of the contact hand onto the superior rib of the dysfunctional intercostal space. Develop preadjustive tension by leaning headward.
At tension, deliver a shallow impulse thrust superiorly and
medially to separate the intercostal space. Take care to avoid
excessive medial pressure to the rib cage. This procedure may
be used to mobilize the intercostal space by applying a slow
stretch instead of an adjustive thrust.
Sitting
Index/Costal Push (Figure 5-196)
IND: Rib dysfunction, R1.
Figure 5-196â•… Index contact established along
5-196
the superior margin of the right first rib to induce distraction and inferior glide in the right first costotransverse
�
articulation.
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| Chiropractic Technique
Figure 5-198â•… Covered-thumb contact over the
5-198
right anterior sixth rib to induce distraction in the
right sixth costosternal articulation.
Figure 5-197â•… Hypothenar contact applied to the right sixth rib angle
to induce distraction in the right fifth costotransverse articulation.
P: Lightly establish the contacts and circumduct the patient’s head
toward the side of rib dysfunction. At tension, deliver an impulse
through the shoulder of the contact hand while simultaneously
delivering a shallow distraction force through the IH.
Hypothenar (Thenar)/Costal Push (Figure 5-197)
IND: Rib dysfunction, R4–R12.
PP: The patient sits with legs straddling the adjusting bench. The
arms are crossed, with the hands grasping the shoulders.
DP: Sit or stand behind the patient.
CP: Hypothenar or thenar of hand corresponding to the side of
contact.
SCP: Just medial to the rib angle.
IH: Your IH and arm reach around the patient to contact the
opposing forearm.
VEC: P-A and L-M.
P: Preadjustive tension is typically developed by flexing, laterally
flexing, and rotating the patient forward on the side of contact.
Once tension is established, deliver an impulse thrust through
the contact hand, assisted by a pulling thrust generated through
your indifferent arm and trunk.
Costosternal Adjustments
Supine
Covered-Thumb/Costosternal Push (Figure 5-198)
IND: Anterior rib dysfunction, R2–R6.
PP: The patient lies supine, with both arms resting on the table.
DP: Stand on the side opposite the adjustive contact.
CP: Thumb of caudal hand.
SCP: Anterior rib just lateral to costosternal junction.
IH: Palm of superior hand covering the thumb and dorsum of the
contact hand.
VEC: M-L and slightly P-A.
P: Slide laterally onto contact with the thumb and reinforce the
contact with the IH. Deliver a shallow and gentle impulse thrust,
emphasizing a lateral VEC to avoid compression of the rib cage.
When applying this procedure to female patients, it is important to ensure that the breast tissue is distracted away from the
Â�doctor’s contact hand and that the patient is properly draped.
Sitting
Hypothenar/Costosternal Pull (Figure 5-199)
IND: Anterior rib dysfunction, R2–R6.
PP: The patient sits with legs straddling the adjusting bench and
arms relaxed in lap.
DP: Sit behind the patient.
CP: Hypothenar of the hand corresponding to the side of adjustive contact.
SCP: Anterior rib just lateral to costosternal junction.
IH: The palm of your superior hand reinforces the dorsum of the
contact hand.
VEC: M-L.
P: Slide laterally onto contact with the hypothenar of the contact hand and reinforce the contact with the palm of the IH.
Develop distractive tension by tractioning laterally and rotating the patient toward the side of adjustive contact. At tension,
deliver a shallow impulse through both arms and the trunk.
Avoid excessive anterior compression of the rib cage by inducing rotation and distraction during the adjustive thrust. When
applying this procedure to female patients it is important to
ensure that the breast tissue is distracted away from the doctor’s
contact hand and that the patient is properly draped.
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Superior articular facet
Transverse
process
Mammillary
process
Spinous
process
Body
Pedicle
Inferior articular facet
Superior articular facet
Mammillary process
Transverse
process
Pars
interarticularis
Lamina
Spinous process
Inferior articular facet
Figure 5-200â•… Posterior view (A) and side view (B) of a lumbar segFigure 5-199â•… Hypothenar contact over the left third anterior rib
to induce distraction in the third costosternal articulation.
LUMBAR SPINE
The most important characteristic of the lumbar spine is that it
must bear tremendous loads created by body weight that interact with forces generated by lifting and other activities involving
powerful muscle actions. In addition to bearing formidable loads,
the lumbar spine is largely responsible for trunk mobility, thereby
placing significant mechanical demands on this region.
ment. (From Dupuis PR, Kirkaldy-Willis WH. In Cruess RL, Rennie
WRJ, eds: Adult orthopaedics, New York, 1984, Churchill Livingstone.)
90°
Functional Anatomy
Figure 5-201â•… Lumbar facet planes. (From White AA, Panjabi
MM: Clinical biomechanics of the spine, ed 2, Philadelphia, 1990, JB
Lippincott.)
The typical lumbar vertebra is a large kidney-shaped structure
designed to carry the heavy loads imposed by upright posture. It is
wider from side to side than from anterior to posterior. The anterior surface of the body is convex from side to side, and the posterior surface is concave from superior to inferior and from side to
side. The superior and inferior surfaces range from flat to slightly
concave (Figure 5-200).
L5 is considered an atypical lumbar vertebra. It has the largest
circumference of all vertebrae, and its body is thicker at its anterior aspect than at its posterior aspect, although the overall thickness of the body is somewhat less than the bodies of the superior
lumbar vertebrae. The transverse processes are short and thick; the
spinous process is shorter and more rounded than the other lumbar vertebrae, and the superior articulating processes are directed
more posteriorly and less medially. The inferior articulating processes are farther apart and are oriented more in the coronal plane,
compared with the normal sagittal orientation of the remaining
lumbar vertebrae.
The lumbar pedicles originate from the upper part of the
vertebra and extend horizontally and posteriorly; the pedicles
are short and strong. The superior vertebral notch is shallow,
and the �inferior vertebral notch is deep. The lumbar laminae
are short, broad, and strong and run in a vertical plane (see
Figure 5-200).
The thick and broad spinous processes are hatchet-shaped
structures that point straight posteriorly. The transverse processes
are long, slender, and flattened on their anterior and posterior surfaces. They originate from the lamina-pedicle junction and are
considered to be quite frail. L3 has the longest of the lumbar transverse processes.
The articular processes are also large, thick, and strong. The
superior articular processes are concave and face posteromedially,
and the inferior articular processes are convex and face anteriorly and laterally. The superior articular processes are wider apart
and lie outside the inferior articular processes. The mammillary
�processes are located on the superior and posterior edge of the
superior articular process.
The lumbar facets lie primarily in the sagittal plane but become
more coronal at the lumbosacral junction (Figure 5-201). This
facet configuration limits rotational flexibility and allows for
greater mobility in flexion and extension (Figure 5-202). The
lumbar facets normally carry 18% of axial load and up to 33% in
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| Chiropractic Technique
L
8
9
R
Approximation
9
10
11
10
11
12
12
L1
L1
Separation
Superior
vertebra
2
2
3
3
4
4
L4
L4 root
L5
S1
L5 root
2
S1
3
2
R
L3 root
Vertebral
bodies
5
5
L
L3
3
4
4
5
Coccygeal
5
Sacrum
Coccyx
Figure 5-204â•… Course of the lumbar nerve roots.
Figure 5-202â•… Right rotation of a lumbar segment, illustrating how
impact of the left facets (compression facet) limits rotation.
Posterior
longitudinal
ligament
Spinal
nerve
Cranial
Nerve
root
L4
Dorsal root
ganglion
Lateral root
ligament
1:3
Dural
sac
Midline dural
ligament
Dural
sac
L5
Lateral
dural
ligament
Posterior
longitudinal
ligament
Caudal
A
B
Figure 5-205â•… Hoffmann’s dural ligaments. A, Posterior view. B,
Lateral view, with the posterior arch removed.
4
4
10
2
Figure 5-203â•… Location of the nucleus and disc height–to–body
height ratio in the lumbar spine.
extended postures. The facets with their articular capsules provide
up to 45% of the torsional strength of the lumbar spine.33,34
The lumbar IVDs are well developed. The nucleus is localized
somewhat posteriorly in the disc, and the disc Â�height–to–body
height ratio is 1:3 (Figure 5-203). This relationship allows for
more movement than the thoracic segments and maintains a
significant preload state, giving the disc’s greater resistance to
axial compressive forces.
The lumbar spinal canal contains, supports, and protects
the distal portion of the lumbar enlargement of the spinal cord
proximally (conus medularis) and the cauda equina with spinal nerves distally. This portion of the central nervous system
is ensheathed in three meninges and tethered to the coccyx by
the filum terminale. Because the cord itself ends at the level of
L2, the nerve roots (NRs) continue down the spinal canal as the
cauda equina. The NRs exit the dura slightly above the foraminal
�opening, �causing their course to be more oblique and their length
to increase (Figure 5-204).
The dural sac and its contents are not freely mobile structures.
A series of ligamentous attachments, called Hoffman ligaments,
define a specific range of movement, thus stabilizing the dural sac
within the foraminal canal (Figure 5-205). Although spinal cord
movements are limited, the spinal cord does demonstrate flexibility during different movements and activities. When flexing
from the neutral position, the length of the spinal canal increases.
This is because the instantaneous axis of motion is located in the
anterior aspect of the vertebral bodies. Similarly, in extension the
canal length decreases. The spinal cord must follow the changes
in the canal during these physiologic movements (Figure 5-206).
It accomplishes this through the mechanisms of folding and
�unfolding, as well as elastic deformation. In the neutral position,
the cord is folded somewhat like an accordion and has slight tension. During flexion the cord first unfolds and then undergoes
elastic deformation. During extension the cord first folds upon
itself, then undergoes elastic compression.
Lumbar Curve
The secondary lordotic lumbar curve starts to develop when a
child is approximately 9 to 12 months of age and beginning to sit
up. As the child learns to stand, the curve becomes established,
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235
35�
rmation
Defo
Full
flexion
zone
Unfold
in
De
g zo
for
ne
ma
ti
on
zo
ne
Full
extension
Figure 5-206â•… Effects of flexion (top left) and extension (top right)
movements on the spinal canal and its contents (cord, meninges, and
nerve roots).
usually by 18 months of age. The lumbar lordosis usually begins
at the L1–2 level and gradually increases at each level caudal to
the sacrum, with the apex of the curve centering around the L3–4
disc.35
Moe and Bratford36 state that the normal lumbar lordosis
should be 40 to 60 degrees but fail to define the levels used
for measurement. The often ill-defined radiographic image of
the superior aspect of the sacrum makes it difficult to use for
measuring the lumbar lordosis. When using the inferior aspect
of the L5 vertebral body and the superior aspect of the L1 vertebral body, a normal range for the lumbar lordosis is 20 to 60
degrees37,38 (Figure 5-207).
In the upright bipedal posture, the lumbar curve, as well as the
rest of the spine, is balanced on the sacrum. Therefore, changes in
the sacral base angle can influence the depth of the A-P curves in
the spine. The sacral base angle increases with an anterior pelvic
tilt, resulting in an increase in the lumbar lordosis, which places
more weight-bearing responsibility on the facets. The sacral base
angle decreases with a posterior pelvic tilt, resulting in a decrease
in the lumbar lordosis, placing more weight-bearing responsibility
on the disc and reducing the spine’s ability to absorb axial compression forces.
Range and Patterns of Motion
The lumbar spine is significantly more flexible in flexion and
extension than any other lumbar movements. Approximately 75%
of trunk flexion and extension occurs in the lumbar spine, with
approximately twice as much flexion occurring as extension. The
first 60 degrees of torso flexion consist of lumbar spine �sectional
Figure 5-207â•… Measurement of the lumbar lordosis, showing a
35-degree curve.
TABLE 5-7
Vertebra
L1–2
L2–3
L3–4
L4–5
L5–S1
verage Segmental ROMs for the
A
Lumbar Spine
Combined
Flexion and
Extension
One-Side
Lateral
Flexion
OneSide Axial
Rotation
12
14
15
16
17
6
6
8
6
3
2
2
2
2
1
Modified from White AA, Panjabi MM: Clinical biomechanics of the spine, ed 2, Philadelphia,
1990, JB Lippincott.
flexion as the pelvis is stabilized by the gluteal and hamstring
muscles. After the lumbar flexion, the pelvis begins to flex, producing an additional 30 degrees of motion. In contrast, lumbar
lateral flexion exhibits only moderate mobility, and axial rotation
is quite limited. The majority of trunk rotation occurs in the thoracic spine. Table 5-7 and Figure 5-24 identify lumbar segmental
ROM.
Flexion and Extension
Combined segmental flexion and extension in the lumbar spine
averages 15 degrees per segment, with motion increasing in an
S-I direction.5,39 Lumbar flexion and extension combines sagittal
plane rotation with an average of 2 to 3â•›mm of sagittal plane translation in each direction.5,40,41 White and Panjabi5 have proposed
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| Chiropractic Technique
that 4.5â•›mm be considered the upper limit for the radiographic
investigation of clinical joint instability. Coupling of lateral flexion
and rotation with flexion and extension have also been noted,28,41
but are considered by White and Panjabi5 to be abnormal patterns
suggestive of suboptimal muscle control.
The precise location of the IAR for lumbar movements has
not been established.5 The IAR for flexion and extension is most
commonly placed within the IVD of the subjacent vertebrae, with
flexion located toward the anterior portion and extension toward
the posterior (Figure 5-208). During flexion the vertebra tilts and
slides anteriorly as the inferior facets move superiorly and away
from the lower vertebra. The disc is compressed anteriorly and
stretched posteriorly. During extension the facets approximate one
another, and the ALL, anterior portion of the joint capsule, and
anterior portion of the disc are stretched (Figure 5-209).
Lateral Flexion
Segmental lateral flexion averages approximately 6 degrees to each
side. Movement is about the same for each segment, with the
exception of the lumbosacral joint, which demonstrates approximately half the movement.5,39 Lateral flexion in the lumbar spine
is coupled with opposite-side rotation (e.g., body rotation to the
LUMBAR
Flexion and
Extension
F
Lateral
Bending
E
F
E
R
Axial
Rotation
L
L
R
L
R
L�R
Figure 5-208â•… Approximate locations for the instantaneous axes of
rotation for the 6 degrees of freedom in the lumbar segments. (From White
AA, Panjabi MM: Clinical biomechanics of the spine, ed 2, Philadelphia,
1990, JB Lippincott.)
Figure 5-209â•… Flexion and extension movements of a lumbar segment.
convexity and spinous deviation to the concavity). This leads to
a pattern in which the spinous processes end up pointing in the
same direction as the lateral flexion (Figure 5-210).5,42 This pattern is opposite to that in the cervical and upper thoracic spine
(see Figures 5-116 and 5-117).
There are several theoretic factors producing coupled rotation during lateral flexion. One important factor is the principle
that it is not possible to bend a curved rod without producing
some rotation. The second force acting on the spine to produce coupled rotation is a product of eccentric muscle activity. Lateral bending is controlled mainly by eccentric activity
of the quadratus lumborum, which inserts posteriorly to the
normal axis of motion. The normal axis is located in the posterior one third of the disc. Therefore, normal muscular activity
leads to posterior rotation of the vertebral bodies on the side of
convexity and rotation of the spinous processes to the side of
concavity.
The IAR for lateral flexion is placed within the subadjacent disc
space.5 For left lateral flexion, the axis is located on the right side,
and for right lateral flexion, on the left (see Figure 5-208). During
lateral flexion, the vertebra tilts and slides toward the �concave
side, producing a smooth, continuous arc. The facets approximate
on the concave side and separate on the convex side. The disc is
�compressed on the concave side and stretched on the convex side.
The ligamentum flavum, intertransverse ligament, and capsular
ligaments are stretched on the convex side.
Grice43 and Cassidy44 have studied the coupling movements
for lateral flexion and have proposed classifying segmental lateral flexion into one of four commonly encountered patterns
(Figure 5-211). In addition, various pathomechanical theories
have been proposed as possible explanations for each abnormal
pattern.
The first pattern, type I movement, exhibits the normal pattern of coupling in which lateral flexion is associated with axial
rotation to the opposite side. This produces a pattern in which
posterior body rotation occurs on the side opposite the lateral
flexion and in which the spinous processes rotate toward the side
of lateral flexion. Purportedly, this pattern is represented when
normal motor control is exerted through eccentric unilateral
Figure 5-210â•… Coupling pattern of lateral flexion with contralateral
rotation in the lumbar spine.
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
Quadratus
lumborum
Sacrospinalis
Multifidus
A
B
Intertransversalis
Multifidus
Quadratus
lumborum
Psoas
C
D
Figure 5-211â•… A, Type I movement of coupled lateral flexion with
contralateral rotation under the control of the quadratus lumborum muscle. B, Type II movement of coupled lateral flexion with ipsilateral rotation under the control of the sacrospinalis and multifidus muscles. This
pattern may be sectional, as shown here, or segmental. C, Type III movement, consisting of segmental aberrant lateral flexion because of faulty disc
mechanics or quadratus lumborum and intertransversalis muscles. D, Type
IV movement, consisting of segmental aberrant lateral flexion and rotation
because of faulty disc mechanics or psoas and multifidus muscles.
�
contraction
of the quadratus lumborum muscle, although synergistic muscles act as a brake to prevent hypermobility. Type I
movement may still be abnormal if it is diminished or excessive
(see Figure 5-211, A).
Type II motion combines lateral flexion and axial rotation
to the same side. This induces posterior body rotation on the
side of lateral flexion and rotation of the spinous process to the
side opposite the lateral flexion. A muscular imbalance of the
sacrospinalis, especially the longissimus and spinalis portions,
is proposed as the source of this abnormal pattern. The semislumped sitting posture may also produce this pattern of movement (see Figure 5-211, B).
Type III movement is represented by aberrant segmental lateral
flexion and normal coupled rotation. With type III movement,
the involved segment demonstrates no lateral flexion or lateral
flexion movement in the direction opposite the bending of the
trunk. This pattern is theorized to result from faulty disc mechanics or overdominance of the quadratus lumborum or intertransversalis muscles (see Figure 5-211, C).
The last pattern, type IV, is represented by aberrant segmental rotation and lateral flexion. This pattern may also result from
faulty disc mechanics or an imbalance in the psoas or multifidus
muscles (see Figure 5-211, D).
These patterns are primarily determined by evaluation of lateral bending functional x-ray studies. The use of lateral flexion and
�flexion-extension movement radiographs has been described
237
(see Figure 3-23) and recommended for evaluation of segmental
motion and instability.43-61 Although functional radiology should be
considered an important potential tool in the evaluation of joint
dysfunction, its limitations should also be realized. There is evidence
to suggest that findings on lateral bending radiographs do not correlate well with back pain and other abnormal clinical findings.53,62
Rotation
Axial rotation is quite limited in the lumbar spine. Segmental
ROM is uniform throughout the lumbar segments and averages
only 2 degrees per motion segment.5,39 The sagittally oriented facet
joints act as a significant barrier to rotational mobility. During
rotation, the facet joints glide apart on the side of rotation and
approximate on the side opposite rotation (see Figure 5-202). The
instantaneous axis for axial rotation is placed within the posterior
nucleus and annulus1 (see Figure 5-208).
Rotation of the lumbar spine is also consistently coupled with
lateral flexion and slight sagittal plane rotation. The coupled lateral
flexion varies between upper and lower lumbar segments. Rotation
in the upper three segments (L1–L3) is coupled with opposite-side
lateral flexion. Rotation in the lower two segments (L4 and S1) is
coupled with same-side lateral flexion.28,63 The transitional change
in coupling that occurs at the L4–5 motion segment may be of
clinical significance in predisposing this level to increased torsional
stress, clinical instability, and degenerative change.5
The pattern of coupled sagittal plane rotation depends on the
starting position of the lumbar spine.28 With the spine in a neutral
starting position, the lumbar spine flexes at all levels when rotated.
When the spine is rotated from a flexed posture, it has a tendency
to extend, and when rotated from an extended posture, it has a
tendency to flex. This pattern was also noted for lateral flexion,
leading to the generalization that “lateral bending or axial rotation
has a tendency to straighten the spine (move it toward a neutral
posture) from the flexed as well as the extended postures.”5
Kinetics of the Lumbar Spine
The control of flexion movements is largely a result of the eccentric contraction of the erector spinae (sacrospinalis) muscles
(Figure 5-212), although it is initiated by concentric contraction
of the psoas and abdominals. The iliopsoas flexes the spine when
the femur is fixed, and the abdominal muscles flex the spine when
the pelvis is fixed. During the first 60 degrees of flexion, the �pelvis
is locked by the gluteus maximus and hamstrings, but after 60
degrees, the weight of the trunk overcomes the stabilizing force
of the glutei and hamstrings, and the pelvis rotates an additional
30 degrees at the hips. In full flexion, all the muscles are relaxed,
except the iliocostalis thoracis, and the trunk is supported by ligaments and passive muscle tension.
The return to neutral is the reverse activity, with the pelvis
moving first under the control of the hip extensors, followed by
extension of the lumbar spine, controlled by erector spinae muscles. Flexion is limited by the ligamentum flavum, PLL, the posterior aspect of the capsular ligament, and interspinal ligament.
Extension is initiated by concentric contraction of the sacrospinalis. Again, after the initial movement, gravity and eccentric
activity of the abdominal muscles become the major controlling
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| Chiropractic Technique
NEUTRAL
A
Erector
spinal
muscles
relax
Gluteal
muscles
relax
60��30�
Gluteal
muscles
contract to
stabilize
pelvis
Gluteal
muscles
contract
Erector
spinal
muscles
contract
NEUTRAL
Figure 5-213â•… Observation of lumbopelvic alignment and posture
with palpation of the posterior iliac spines and iliac crests.
B
Figure 5-212â•… Flexion of the trunk. A, The first 60 degrees of flexion
involve eccentric contraction of the lumbar paraspinal muscles, followed
by an additional 30 degrees of hip flexion after relaxation of the gluteal
muscles. B, In extension, the converse occurs.
forces in extension. Extension is limited by the ALL and anterior annulus and most significantly by bony impact of the spinous
�processes and articular facets.
Lateral flexion is initiated by concentric contraction of the
quadratus lumborum on the ipsilateral side and then immediately controlled by eccentric activity of the contralateral quadratus
lumborum. Lateral flexion movement is limited by impact of the
articular facets on the side of bending, and the capsular ligaments,
ligamentum flavum, intertransverse ligament, and deep lumbar
fascia on the contralateral side.
Rotation is initiated by concentric activity of the abdominal obliques
and assisted by concentric activity of the short segmental muscles (multifidus and rotatores) on the contralateral side. Rotational movements
are controlled or limited by eccentric activity of the ipsilateral multifidus and rotatores (although mainly limited by facetal design), as well as
the capsular, interspinous, and flaval ligaments. Balancing contraction
of the contralateral muscles is important in maintaining the normal instantaneous axis of motion for axial rotation.
Evaluation of the Lumbar Spine
Observation
The assessment of lumbar function should begin with an evaluation of lumbopelvic alignment and ROM. The sacral base forms
the foundation of the spine, and a functional or structural alteration in the pelvis or lower extremities may alter the alignment of
the lumbar spine and segments above. Pelvic and hip alignment
Figure 5-214â•… Posterior plumb line observation, demonstrating pelvic
unleveling low on the right, with a right convex curve in the lumbar spine.
are evaluated by observing the alignment of the gluteal folds, posterior iliac spines (sacral dimples), and iliac crests.
To palpate the alignment of the pelvis, place the thumbs on
the posterior iliac spines and the fingertips along the superior
margin of the crests (Figure 5-213). Compare each side for symmetry and their orientation to the greater trochanter for possible
leg length inequality.
Coronal plane alignment of the lumbar spine is evaluated by
observing the orientation of the spinous process, status of the
paraspinal muscles, and contours of the waist (Figure 5-214).
Scoliotic curvatures in the lumbar spine are frequently represented by muscle asymmetry and increased paraspinal muscle
mass on the convex side of scoliosis. Compensatory curvatures are
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
common in the lumbar spine, and any noted deviations should be
followed up with an assessment of leg length.
Sagittal plane orientation of the hips, pelvis, and lumbar spine
is evaluated from the side. The lumbosacral angle in large part
determines the angle of the lumbar curve and is often mirrored by
the positioning of the pelvis. Anterior or posterior tilting of the
pelvis usually results from alterations in the hip angle. Anterior
pelvic tilt results from bilateral hip flexion, and posterior pelvic tilt
results from bilateral hip extension (Figure 5-215).
Anterior pelvic tilt increases the lumbosacral angle and lumbar curve; posterior pelvic tilt reduces the lumbosacral angle and
curve. The lumbar curve also alters its angle relative to �structural
alteration in the thoracic curve. Congenitally straight thoracic
curves often lead to straightening of the lumbar and cervical
curves. Increased thoracic kyphosis may lead to accentuation of
the lumbar and cervical curves.
Lumbopelvic movement should be observed for range and symmetry. Flexion, extension, and lateral flexion are usually assessed
with the patient standing. Rotation is more effectively evaluated
in the sitting position to fix the pelvis and prevent hip rotation.
239
To assess flexion, the patient bends forward, and any limitations, painful arcs, or alterations in normal sequencing are
observed. With normal range, the patient should be able to come
within several inches of the floor with the fingertips, and the lumbar curve should reverse (Figure 5-216).
A
A
B
Figure 5-215â•… Observation of posture from a lateral view, showing an
anterior pelvic tilt with lumbar hyperlordosis (A) and a posterior pelvic
tilt with lumbar hypolordosis (B).
B
Figure 5-216â•… Observation of thoracolumbar range of motion.
A, Flexion. B, Extension.
(Continued)
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| Chiropractic Technique
C
D
Figure 5-216—Cont’dâ•… C, Lateral flexion. D, Rotation.
After the patient returns to neutral, the doctor should stabilize the patient’s hips while extension is performed. Extension is
significantly more limited than flexion, and mild midline lumbosacral discomfort is commonly associated with full extension.
Lateral bending is evaluated by instructing patients to bend to
one side while running their fingers down the lateral surface of
the leg. It is important to ensure that the patient does not �axially
rotate the trunk, bend the knee, or raise the foot off the floor
while bending. The movement should be symmetric, and the doctor should record where the patient’s fingertips pass relative to the
knees. A smooth C curve should be observed to the side of bending. Areas of regional restriction or increased movement may be
noted by observing for a sudden break (bent-stick configuration)
in integrated movement.
To isolate movements of the lumbar spine from hip and thoracic movements, the doctor may use inclinometric methods and
measure movement between the thoracolumbar and lumbosacral
regions. Table 5-8 lists the normal ranges for lumbar movement;
the methods for measuring movement have been previously
described (see Figure 3-10).
TABLE 5-8
Global ROMs for the Lumbar Spine
Flexion
Extension
One-Side Lateral Flexion
One-Side Axial Rotation
40–60 degrees
20–35 degrees
15–25 degrees
5–18 degrees
Static Palpation
To evaluate the bony and soft tissue structures of the lumbar spine,
the patient is placed in the prone position and scanned for areas of
potential tenderness, misalignment, or asymmetry.
To scan the bony landmarks, use the pads of the fingers or
thumbs and palpate the spinous processes, interspinous spaces, and
mammillary processes (Figure 5-217). Palpation of the interspinous
spaces is enhanced by placing a small roll under the �abdomen or
elevating the lumbar and pelvic sections of an articulating table.
The mammillary processes are not distinctly palpable; rather, the
doctor feels for a sense of firmness in the soft tissue as the contact
passes over each mammillary process. Rotational prominence of
lumbar spinal segments is perceived by a sense of fullness in the
muscles over the top of the mammillary processes and not by actual
palpation of bony rotation.
Palpation of the lumbar paraspinal soft tissues is conducted
by applying bilateral contacts with the palmar surfaces of the fingers or thumbs. Evaluation should incorporate an assessment of
tone and texture of the erector spinae, quadratus lumborum, deep
segmental muscles, and iliolumbar ligaments. The psoas muscle
should also be palpated for tone and tenderness. The psoas is accessible for palpation in the supine position, and the belly becomes
more evident by inducing hip flexion on the side of palpation.
Motion Palpation
Joint Play.╇ The lumbar spine may be scanned in the sitting
or prone position for sites of painful or restricted JP. Sites of suspected abnormality should be further assessed with specific JP
Chapter 5â•… The Spine: Anatomy, Biomechanics, Assessment, and Adjustive Techniques |
A
241
B
Figure 5-217â•… Palpation of lumbar interspinous alignment and sensitivity (A) and paraspinal muscle tone, texture, and sensitivity (B).
B
A
5-218
Figure 5-218╅ Lumbar joint play evaluation for posterior-to-�anterior glide. A, Bilateral thenar contacts over the
mammillary processes. B, Digit contact over the spinous process.
tests. The same methods applied in the thoracic spine for assessing P-A glide and counter-rotation may be applied to the lumbar
spine (Figure 5-218). Additional options include the evaluation of
rotation, the assessment of lateral glide, and a side-posture method
for evaluating possible instability.
To assess rotational JP, the doctor contacts adjacent spinous
processes (Figure 5-219) or the spinous process and the anterior
crest of the ilium and applies counter-rotation across the joint.
Normal movement is pain-free and is associated with a sense of
giving with pressure and recoil when pressure is released.
Lateral glide of individual lumbar motion segments may be
evaluated with the patient in the prone position by establishing
a thumb contact against the lateral surface of adjacent spinous
processes with the cephalic hand while the other hand grasps the
patient’s anterior and medial thigh (Figure 5-220). Movement is
induced by applying medial pressure against the spinous process
while the patient’s leg is passively abducted. Normal movement is
represented by segmental bending and shifting of the spinous process away from the contact. This procedure can also be performed
by moving the pelvic section of a flexion table from side to side.
To evaluate segmental stability in side posture, place the patient
on either side, with the upper thigh and knee flexed. Establish
a fingertip contact over the spinous processes and interspinous
spaces with the cephalic hand and straddle the patient’s flexed
knee (Figure 5-221). Apply posterior shearing pressure through
the patient’s knee and gentle anterior pressure through the palpation hand. Feel for gliding between adjacent spinous processes.
Excessive posterior glide (translation) of the inferior spinous
�process relative to the superior spinous process suggests possible
clinical joint instability.
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| Chiropractic Technique
Figure 5-219â•… Counter-rotational joint play
5-219
evaluation for left rotational movement of L3 relative to L4. Opposing forces are directed toward the midline through a
contact established on the left side of the L3 spinous process and the right
side of the L4 spinous process.
Figure 5-220â•… Lumbar joint play evaluation for
5-220
lateral glide in the L3–4 motion segment, using a
thumb contact across the left L3–4 interspinous space.
Lumbar Segmental Motion Palpation and End Play. Lumbar
segmental motion may be evaluated with the patient in the sitting or side-posture positions. Both postures are effective for
assessing lumbar mobility, but side-posture positions do not provide as much freedom for full trunk movement. This is especially
true for the evaluation of lumbar lateral flexion and end play.
Sitting Methods. For sitting evaluations, place the patient on an
adjusting bench or palpation stool with the arms crossed over the chest.
The doctor may sit behind or stand beside the patient. Movement is
controlled through contacts on the patient’s shoulders.
Rotation. Lumbar segmental rotation is evaluated by establishing a thumb contact against the lateral surface of adjacent spinous
Figure 5-221╅ Side-posture evaluation for �lumbar
5-221
clinical instability, with the doctor applying an anterior-to-posterior force along the line of the shaft of the patient’s femur while
palpating for increased translational movement between L3 and L4.
processes. The contact is placed on the side of induced rotation so
that the pad spans the interspinous space. The support hand reaches
around the front of the patient, hooks the patient’s anterior shoulder
or grasps the opposite forearm, and rotates the patient’s trunk toward
the side of contact (Figure 5-222). During normal rotation the doctor should palpate the superior spinous process, rotating away from
the spinous process below. Movement should occur in the direction
of trunk rotation. If separation is not noted and adjacent spinous
processes move together, segmental restriction should be suspected.
Lumbar segmental movement is quite limited in rotation (1€to
2 degrees), and the examiner may not be able to discriminate
reductions of movement within these